Southern Living French Onion Soup Casserole Recipe
There’s just something about French Onion Soup that feels like a warm hug from home, isn’t there? The caramelized onions, the gooey melted cheese, that rich, savory broth—it’s no surprise it’s a classic. Now, picture all those amazing flavors turned into a cozy, shareable casserole that’s even easier to serve. That’s exactly what Southern Living’s French Onion Soup Casserole brings to the table, and food lovers everywhere can’t get enough of it!
Equipment
- Large skillet
- 9x13-inch baking dish
- Sharp Knife
- Cutting board
- Wooden spoon
- Measuring Cups
- Measuring spoons
Ingredients
For the Onion Mixture
- 4 large yellow onions thinly sliced
- 4 tablespoons unsalted butter
- 2 tablespoons olive oil
- 4 cups beef broth preferably low-sodium
- 1 teaspoon sugar
- 2 teaspoons fresh thyme leaves or 1 teaspoon dried thyme
- Salt and pepper to taste
For the Casserole Base
- 1 loaf of crusty French bread cut into 1-inch cubes
- 2 cups shredded Gruyère cheese or your favorite melting cheese
- 1 cup grated Parmesan cheese
Instructions
Step 1: Get Your Ingredients Ready
- Start by slicing the onions nice and thin so they cook evenly and release all that sweet, delicious flavor. Gather the rest of your ingredients—broth, cheese, seasonings—and keep everything within arm’s reach. Trust me, a little prep here will make the cooking process way smoother and save you time later.
Step 2: Caramelize the Onions
- Grab a large skillet, heat it over medium, and toss in some butter or oil. Once it’s hot, add your sliced onions and give them a good stir. Let them cook slowly, stirring often, until they turn that perfect golden brown. This can take 20 to 30 minutes, but it’s so worth it—the deep, rich flavor is what makes French onion soup so amazing.
Step 3: Mix It All Together
- When your onions are beautifully caramelized, it’s time to add the seasonings and pour in the broth (or any other liquid you’re using). Scrape up all the tasty bits from the skillet and stir everything together. Let it simmer gently so the flavors can blend and fill your kitchen with that mouthwatering aroma.
Step 4: Build the Casserole
- Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish to keep things from sticking. Pour the onion mixture into the dish, then top it off with slices of crusty bread or croutons. Don’t be shy with the cheese here—sprinkle it generously over the top to cover everything.
Step 5: Bake It Up
- Slide the casserole into the oven and bake until the cheese is melted, bubbly, and just starting to turn golden brown—about 20–25 minutes. This part is pure magic as all those flavors come together into one irresistible dish.
Step 6: Dig In and Enjoy
- Take the casserole out of the oven and let it cool for a few minutes (if you can wait that long). Scoop it onto plates or bowls, pair it with a simple salad or your favorite drink, and enjoy the cozy, savory goodness of this French onion soup casserole. It’s comfort food at its finest—bon appétit!
Notes
When making this recipe, ensure you caramelize the onions properly to bring out their natural sweetness, as this is key to the dish's rich flavor. Also, allow the casserole to rest for a few minutes after baking to help the flavors meld together. Using freshly grated cheese will enhance the overall taste and texture of the dish.