How to make French onion soup casserole (video)

Emma Blecker

Contributing Writer

A brilliant French onion soup has the uncanny ability to take the edge off a bad day. Hearty, savory, packed with incredible flavor and topped with intensely satisfying Gruyere cheese, this traditional dish has been comforting generations upon generations for a reason! Many may not even think it reasonable to make a homemade version due to the need for freshly caramelized onions, which can be seen as a daunting endeavor for first-time caramelizers.

On the contrary, caramelizing onions yourself is as easy as it gets! It takes longer than you might expect, approximately 45 minutes, but much of this time is completely hands off, and the end result will leave you absolutely breathless. A great trick is to caramelize more onions than you need for this recipe and save the extra onions in the fridge to use later in the week to liven up a roast chicken dinner or a side of mashed potatoes. Once you have access to this delicious ingredient, you won't ever look back!

Cooktop Cove

French onion soup casserole

15 minutes

1 hour, 15 minutes

1 hour, 30 minutes

2 tablespoons butter

1 bay leaf

2 teaspoons thyme

1 teaspoon parsley

½ teaspoon salt

¼ teaspoon pepper

3 large sweet onions, thinly sliced

1 tablespoon olive oil

Half a French baguette, sliced 1 inch thick

1 tablespoon flour

1½ cups beef stock

2 cups shredded Gruyere cheese

Begin by caramelizing the onions. In a large frying pan over medium heat, melt the butter along with the bay leaf, thyme, parsley, salt and pepper. Pour in the sliced onions and leave to caramelize for 45 minutes, stirring every 10 minutes to ensure that they are not burning (although you want them to brown a little bit). Remove from heat and set aside.

Preheat the oven to 350 degrees Fahrenheit. Lightly grease a 3-quart casserole dish or 9-by-13-inch casserole pan with the olive oil. Place the French baguette slices on the bottom of the casserole dish. Spoon the caramelized onions evenly over the top.

In a small bowl, quickly mix the flour together with the beef stock before pouring over the bread and onions.

Sprinkle the grated Gruyere cheese over the top of the casserole along with a pinch of salt and freshly ground black pepper. Cover the casserole with foil and bake in the preheated oven for 30 minutes.

Pro tip: We always recommend caramelizing more onions than this recipe calls for and saving any extras in the fridge for later use!

Pro tip: For an even richer French onion soup flavor, simmer caramelized onions in broth for 30 to 45 minutes first, then pour over the bread and continue with step 2.

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