Servings: Serves 6 to 8 hungry souls
Ingredients:
– 3 tablespoons of unsalted butter
– 3 large sweet onions, thinly sliced
– 2 cloves garlic, minced
– Salt and pepper, to taste
– 1 teaspoon of thyme, fresh or dried
– 2 tablespoons of all-purpose flour
– 1/2 cup of dry white wine
– 2 cups of beef broth
– 1 cup of chicken broth
– 6 slices of day-old French bread or baguette, toasted
– 1 1/2 cups of grated Gruyère cheese
– 1/2 cup of grated Parmesan cheese
– 1/4 cup of fresh parsley, chopped (for garnish)
– Cooking spray for the baking dish
Directions:
1. Preheat your oven to 400°F (200°C) and spray a 9×13 inch baking dish with cooking spray.
2. Melt butter in a large pan over medium heat. Add sliced onions and cook, stirring occasionally until they’re soft, sweet, and golden brown (about 15 minutest). Stir in garlic, salt, pepper, and thyme; cook for another minute.
3. Sprinkle the flour over the onions, cook for a couple of minutes to remove the raw flour taste, and then pour in the wine. Let it simmer until the liquid reduces slightly, then add both broths. Bring to a simmer and cook for another 10 minutes.
4. Pour half of the onion mixture into the prepared baking dish. Layer half of the toasted bread on top, then sprinkle with half of the Gruyère and Parmesan cheeses. Repeat the layers with the remaining ingredients.
5. Pop the dish into the oven and bake uncovered for 20-25 minutes, or until the cheese is bubbly and starting to get those irresistible browned edges.
6. Once it’s done, let it sit for a few minutes to set. Sprinkle with fresh parsley before serving for a pop of color and freshness!

Variations & Tips:
– Veggie Swap: Not into beefy flavors? Feel free to swap the beef broth with more chicken or even veggie broth.
– Cheese Twist: Experiment with different cheeses. A sharp cheddar or a slice of mozzarella can work wonders too.
– Gluten-Free? No problem! Opt for a gluten-free bread option to crisp up and layer in.
– Storing: This casserole can be prepped a day in advance. Just assemble, cover, and store in the fridge until you’re ready to bake.
– Busy Bee Tip: If you’re pressed for time, go ahead and use caramelized onions from the store – I won’t tell if you don’t!