By Becky Hardin
Updated Aug 14, 2025
French Onion Soup Casserole is the perfect combination of a classic soup and an easy casserole recipe. I love that you get all the delicious flavors from the caramelized onions, crunchy baguette, and gooey cheese in an easy-to-make weeknight dinner!
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5-Star Review
“This is a great recipe! If my family had their way, I would make it every day” – Chelsea
Easy French Onion Soup Casserole
French onion soup has always been one of my favorites—it’s such a classic for a reason. That slightly sweet, deeply savory flavor topped with golden croutons and melty cheese? I can never resist.
And since I’m all about easy, comforting meals, it only made sense for me to turn those flavors into a casserole. This French Onion Soup Casserole has all the goodness of the soup—caramelized onions, crispy baguette slices, and plenty of gooey cheese—without needing a bowl or hours in the kitchen.
It’s rich, cozy, and just as satisfying as the classic, but way easier to make on a busy weeknight.
Ingredients1x2x3x
- ▢ 16 oz. baguette cut into ¼-inch slices (1 loaf)
- ▢ ¼ cup unsalted butter (½ stick)
- ▢ 2 Vidalia onions halved and cut top-to-bottom into ¼-inch-slices
- ▢ 3 yellow onions halved and cut top-to-bottom into ¼-inch-slices
- ▢ 1 tsp kosher salt
- ▢ ½ tsp freshly ground black pepper
- ▢ 5 fresh thyme sprigs leaves removed
- ▢ 1 bay leaf
- ▢ ½ cup dry sherry
- ▢ 1 cup unsalted beef broth
- ▢ 2 cups unsalted chicken broth
- ▢ 8 oz. freshly shredded Gruyere cheese (about 2 cups)
Video
Instructions
- Preheat oven to 400°F and set the oven rack to the lower-middle position. Spray a 9×13-inch baking dish with nonstick cooking spray and set aside.
- Place the baguette slices on a metal rack placed inside a baking sheet and bake for 8-10 minutes or until golden brown. Remove from the oven and set aside until ready to use. 16 oz. baguette
- While the bread slices toast, generously spray the inside of a large Dutch oven with nonstick cooking spray. Slice the onions (if they haven’t already been sliced). 2 Vidalia onions, 3 yellow onions
- Add the butter, sliced onions, salt, black pepper, thyme leaves and bay leaf to the Dutch oven. ¼ cup unsalted butter, 1 tsp kosher salt, ½ tsp freshly ground black pepper, 5 fresh thyme sprigs, 1 bay leaf
- Once the baguette slices have toasted, cover the Dutch oven tightly and cook the onions 1 hour. Remove pot from oven and stir, being sure to scrape the sides and bottom of pot.
- Return the pot to the oven with the lid slightly ajar and continue cooking another 1 hour.
- Once again, remove the pot from the oven and stir the onions (scraping the sides and bottom). The onions will be soft and a little darker than golden brown. If the onions need more color, return the pot to the oven (still with the lid slightly ajar) and cook another 30 minutes.
- Transfer the pot to the stovetop and turn the heat to medium-high. Remember – the pot is HOT! Use oven mitts when touching the handles.
- Remove and discard the bay leaf from the onions.
- Add sherry, beef broth and chicken broth; bring to a boil, stirring constantly, until slightly thickened, about 4-5 minutes. ½ cup dry sherry, 1 cup unsalted beef broth, 2 cups unsalted chicken broth
- Layer half the toasted baguette slices in the prepared casserole dish.
- Spoon onion mixture evenly over the bread, and top the remaining bread slices.
- Sprinkle with shredded cheese and cover with foil. 8 oz. freshly shredded Gruyere cheese
- Bake at 400°F for 30 minutes.
- Set the heat to broil and remove the foil.
- Broil 3 minutes or until cheese is bubbly. Watch closely.
- Garnish with additional thyme leaves, if desired.
Equipment
- 9×13 Baking Pan
- Baking Sheet
Nutrition information is automatically calculated, so should only be used as an approximation.
How to Make French Onion Casserole Step by Step
Get the oven going and prepare a baking dish: Preheat the oven to 400°F and set the oven rack to the lower-middle position. Spray a 9×13-inch baking dish with nonstick cooking spray and set aside.
Bake the baguette : Bake the baguette slices in the oven at 400°F for 8-10 minutes and set aside.
Prepare the onions: Cut 2 Vidalia onions and 3 yellow onions.
Add ¼ cup unsalted butter, 1 tsp kosher salt, ½ tsp freshly ground black pepper, 5 fresh thyme sprigs, and 1 bay leaf into the prepared Dutch oven.
Cook the onions: Cook the onions in the oven at 400°F. After 1 hour, stir the onions and then place them back in the oven, with the lid slightly ajar. Cook another hour and stir again.
Transfer the pot of onions to the stove top and place over medium-high heat. Remove the bay leaf.
Add in the ½ cup dry sherry, 1 cup unsalted beef broth, and 2 cups unsalted chicken broth. Bring the mixture to a boil, stirring constantly, for about 4-5 minutes until it has thickened.
Make the casserole: Layer half of the baguette slices into the casserole dish. Then spoon the onions over each bread slice, and top with the remaining slices. Sprinkle the 8 oz. of cheese over everything.
Cover the casserole dish with foil, and bake for 30 minutes at 400°F.
After that, remove the foil, switch the oven to broil, and broil the casserole for about 3 minutes to make the cheese bubbly and golden brown.
Serve: Serve and enjoy!
How to Store
If you want to do some prep ahead of time, the baguette slices can be made up to 5 days ahead and kept in an airtight container until ready to use.
The caramelized onions can be made up to 3 days ahead and kept refrigerated, in an airtight container, until ready to use.
Store leftover French onion soup casserole in an airtight container in the refrigerator for up to 4 days.
Serving Suggestions
I like to serve this French onion soup casserole with a few light veggie-oriented sides, like a green goddess salad and either grilled veggies or air fryer roasted veggies to offset the rich cheesiness.
more casserole options to try
Garlic Bread Pepperoni Pizza Casserole
King Ranch Chicken Casserole
Beef Stroganoff Casserole
Sausage and Potato Casserole
French Onion Soup Casserole
Equipment
- 9x13 Baking Pan
- Baking Sheet
Ingredients
- 16 oz. baguette cut into ¼-inch slices (1 loaf)
- ¼ cup unsalted butter (½ stick)
- 2 Vidalia onions halved and cut top-to-bottom into ¼-inch-slices
- 3 yellow onions halved and cut top-to-bottom into ¼-inch-slices
- 1 tsp kosher salt
- ½ tsp freshly ground black pepper
- 5 fresh thyme sprigs leaves removed
- 1 bay leaf
- ½ cup dry sherry
- 1 cup unsalted beef broth
- 2 cups unsalted chicken broth
- 8 oz. freshly shredded Gruyere cheese (about 2 cups)
Instructions
- Preheat oven to 400°F and set the oven rack to the lower-middle position. Spray a 9x13-inch baking dish with nonstick cooking spray and set aside.
- Place the baguette slices on a metal rack placed inside a baking sheet and bake for 8-10 minutes or until golden brown. Remove from the oven and set aside until ready to use. 16 oz. baguette
- While the bread slices toast, generously spray the inside of a large Dutch oven with nonstick cooking spray. Slice the onions (if they haven’t already been sliced). 2 Vidalia onions, 3 yellow onions
- Add the butter, sliced onions, salt, black pepper, thyme leaves and bay leaf to the Dutch oven. ¼ cup unsalted butter, 1 tsp kosher salt, ½ tsp freshly ground black pepper, 5 fresh thyme sprigs, 1 bay leaf
- Once the baguette slices have toasted, cover the Dutch oven tightly and cook the onions 1 hour. Remove pot from oven and stir, being sure to scrape the sides and bottom of pot.
- Return the pot to the oven with the lid slightly ajar and continue cooking another 1 hour.
- Once again, remove the pot from the oven and stir the onions (scraping the sides and bottom). The onions will be soft and a little darker than golden brown. If the onions need more color, return the pot to the oven (still with the lid slightly ajar) and cook another 30 minutes.
- Transfer the pot to the stovetop and turn the heat to medium-high. Remember – the pot is HOT! Use oven mitts when touching the handles.
- Remove and discard the bay leaf from the onions.
- Add sherry, beef broth and chicken broth; bring to a boil, stirring constantly, until slightly thickened, about 4-5 minutes. ½ cup dry sherry, 1 cup unsalted beef broth, 2 cups unsalted chicken broth
- Layer half the toasted baguette slices in the prepared casserole dish.
- Spoon onion mixture evenly over the bread, and top the remaining bread slices.
- Sprinkle with shredded cheese and cover with foil. 8 oz. freshly shredded Gruyere cheese
- Bake at 400°F for 30 minutes.
- Set the heat to broil and remove the foil.
- Broil 3 minutes or until cheese is bubbly. Watch closely.
- Garnish with additional thyme leaves, if desired.
Video
Nutrition
By Becky Hardin
Published Jul 12, 2017
This Essential Grocery List is an absolute life saver for my family on the busy weeks. When I started this journey to learn how to cook, I quickly realized that the first step in cooking is having staple ingredients on hand. I want to avoid having to run out to the grocery store every single time I prepare a new recipe. Having a well-stocked pantry has made my life in the kitchen so much simpler, because when it’s time to cook, I have what I need.
Essential Grocery List
It’s so helpful to have a basic grocery list to help me remember which foods to buy at the store. This food shopping list is my go-to!
It’s better to stock up on things like grains, seasonings and spices, baking essentials, oils, condiments, canned and frozen foods, etc. so I can just grab them when I need them. These things have a long shelf life , so I keep them in my kitchen for convenience.
However, I do have to go to the supermarket sometimes, and there’s a way to make that trip easy and hassle-free: I keep a grocery list! If I go in blindly, I’ll leave with things I don’t need, and nothing that actually helps me prepare a good meal.
In the list below, I’ve compiled everything I always have on my stock-up grocery list.
I’ve got you covered! I created an easy grocery list filled with all of the essentials. Plus there’s a free printable version that you can take with you to the grocery store. It has everything you need to stock your pantry, your freezer, and your refrigerator.
Click to get my Free Printable Grocery List
What to Buy at the Grocery Store
This is the perfect grocery list filled with all the basics and essentials. It should help get you going if you’re new to cooking, or if you’re just left staring helplessly at an empty pantry and don’t know how to fill it.
When I first started cooking, things could seem overwhelming. I quickly realized that they more prepared I could be, the more confident I felt. If you already have the basics in your kitchen, then you can shop stress-free.
So print out our easy grocery list, stock up your pantry and fridge, and you’ll be cooking in no time!
Click to get my Free Printable Grocery List for the perfectly stocked pantry and freezer!
Fresh Produce
- Apples
- Bananas
- Strawberries
- Avocados
- Bell Peppers
- Carrots
- Broccoli
- Garlic
- Lemons/Limes
- Onion
- Parsley
- Cilantro
- Basil
- Potatoes
- Spinach
- Tomatoes
GRAINS
- Breadcrumbs
- Pasta
- Quinoa
- Rice
- Sandwich Bread
- Tortillas
MEAT/PROTEIN
- Chicken
- Eggs
- Ground Beef
- Sliced Turkey
- Lunch Meat
DAIRY
- Butter
- Sliced Cheese
- Shredded Cheese
- Milk
- Sour Cream
- Greek Yogurt
BAKING GOODS
- Baking powder
- Baking Soda
- Granulated Sugar
- Brown Sugar
- Flour
- Honey
- Vanilla Extract
- Dry Yeast
- Chocolate Chips
- Cocoa Powder
- Powdered Sugar
FREEZER
- Fruit and Berries
- Frozen Veggies (Corn, Peas, Broccoli, etc)
- Juice Concentrate
- Pizza or Other Convenience Meals
- Pie Crust
- Cookie Dough
CANNED/DRIED GOODS
- Chicken stock/broth
- Salsa
- Diced Tomatoes
- Jam/Jelly
- Peanut Butter
- Pasta Sauce
- Beans (Black Beans, Chickpeas, Baked Beans, etc)
- Soups
- Tuna
- Green Chiles
- Canned Veggies
- Coffee or Tea
Get more details on the best non-perishable and pantry foods
CONDIMENTS/SPICES
- Black Pepper
- Chili Powder
- Cinnamon
- Crushed Red Pepper
- Cumin
- Garlic Powder
- Ketchup
- Mustard
- Mayo
- Nutmeg
- Paprika
- Salt (Course Sea Salt and Kosher Salt)
- Soy Sauce
- Steak Sauce
- Hot Sauce/ Buffalo Sauce
- Salad Dressings
OILS/VINEGARS
- Apple cider vinegar
- Balsamic vinegar
- Coconut Oil
- Olive Oil
- Vegetable/Canola Oil
- Red Wine Vinegar
- White Vinegar
- Cooking Wine
- White Wine Vinegar
SNACKS
- Crackers
- Nuts
- Quick Oats
- Popcorn
- Tortilla Chips
- Cereal
Click to get my Free Printable Grocery List for the perfectly stocked pantry and freezer!
Click ☝🏻 for my FREE Grocery List Printable!
I hope this essential grocery list can help you buy what you need and make your home cooking so much easier!
Stock Your Kitchen
Find more ideas for your grocery list, stock up your kitchen, and print more cooking guides and charts to keep handy!
Non-Perishable Foods to Stock Up On
Frozen Vegetables to Stock Up On (and Recipes to Make)
Ultimate List of Cooking Herbs for Your Kitchen
Ultimate List of Cooking Spices for Your Kitchen
Cooking Oil 101: Types of Cooking Oils to Use
26 Types of Pasta and When to Use Them
What Fruits and Vegetables are in Season?
Meat Temperature Chart (Free Printable)
How to Meal Prep (Guide for Beginners)
Basic Cooking Measurements & Kitchen Conversion Chart
