Baked French Onion Soup Casserole


Baked French Onion Soup Casserole

This baked onion casserole with french bread is easier to make than french onion soup and just as yummy.

This incredibly tasty soup and casserole combo is the perfect dish for a fall dinner. Our decadent recipe for a french onion soup casserole is easy to cook up. Simpler than traditional soup recipes, this easy peasy treat involves minimal prep. Just carmelize your onions and then set your baked onion casserole with french bread in the oven to sizzle on its own.

From the Chef: When people ask what my favorite thing to cook is, I usually say it's something that lets me stand over the stove and stir, but then allows me to leave it behind and socialize. This dish is a good example of just that. I love the act of sautéing the onions and garlic, watching the butter melt, and patiently waiting as the onions decide to brown. At just the right time, when my guests arrive and I want to step away from the stove, this casserole is ready to be poured into a pan and baked. It's a sit-by-the-fire, read-a-book, and snuggle-up kind of casserole, one that I hope you enjoy as much as I do.
 - Addie Gundry

This recipe is from RecipeLion's 103 Cookbook seriesFamily Favorite Casserole Recipes: 103 Comforting Breakfast Casseroles, Dinner Ideas, and Desserts Everyone Will Love.


Preparation Time30 min

Cooking Time55 min



  • 2 tablespoons unsalted butter
  • 3 large yellow onions, thinly sliced
  • 1 teaspoon sugar
  • 1 cup chicken broth
  • 1 cup beef broth
  • 1 teaspoon chopped fresh thyme
  • 1 teaspoon Dijon mustard
  • 1 teaspoon kosher salt
  • 1 teaspoon freshly ground black pepper
  • 1 baguette, sliced 1/2 inch thick (24 slices)
  • 2 cups shredded Gruyère cheese
  • Fresh thyme, for garnish


  1. Preheat the oven to 350°F and lightly coat a 9 x 13-inch baking dish with cooking spray. Line a baking sheet with parchment paper.

  2. In a large saucepan, melt the butter over medium heat. Add the onions and cook, stirring occasionally, until the onions are soft and golden. Halfway through the cooking, around 2 minutes, add the sugar to help the onions caramelize. When the onions are done, add the chicken and beef broths, thyme, mustard, salt, and pepper. Simmer for 5 to 10 minutes.

  3. Place the bread slices on the parchment-lined baking sheet and toast 2 to 3 minutes on each side.

  4. Place half of the bread slices in the baking dish, overlapping slightly.

  5. Layer half of the onion mixture on top of the bread slices. Top with remaining bread slices, then the remaining onion mixture. Cover with the cheese. Cover with foil and bake until hot and bubbling, 30 to 35 minutes. Garnish with fresh thyme and serve.

Your Recently Viewed Recipes

Leave a Comment


Cancel Reply to Comment

Thanks for your comment. Don't forget to share!

This is a little different than your traditional french onion soup but perfect for this time of year...and you'd never know by the looks of the picture how easy it is to make. Is gruyere normally the cheese that is used in French onion soup, I don't know why but I've always thought it had Swiss cheese in it.

Um YES! This looks absolutely divine.

This looks like a great idea for lunch on a cold day, sitting around the kitchen table or in front of a fire with a good book. I love casseroles and french onion soup, so this is right down my alley. One question....are yellow onions the same thing as white onions or do they have a different flavor?

yellow and white onions are different and have a slightly different taste.

This easy recipe is right up my alley! I agree with Addie, the recipes that you can stir and step away from are ideal for when you're having company over.

I really love French Onion soup, and I've never thought about turning it into a casserole before. Learn something new every day, I guess. This sounds like a great thing to serve at a potluck, or it could make a nice wintertime evening meal. It's definitely a different approach to one of my favorite soups and I'm glad you shared it.


Report Inappropriate Comment

Are you sure you would like to report this comment? It will be flagged for our moderators to take action.

Thank you for taking the time to improve the content on our site.

Close Window