Ingredients (4 servings)
For the soup
4 large yellow onions, thinly sliced
3 tbsp butter
1 tbsp olive oil
2 cloves garlic, minced
4 cups beef broth (or vegetable broth)
½ cup dry white wine (optional)
1 tsp fresh thyme leaves
Salt and black pepper to taste
For topping
4 small croissants
1½ cups grated Gruyère cheese
½ cup grated Parmesan cheese
1 cup sliced mushrooms, sautéed
Extra thyme for garnish
Instructions
Caramelize the onions
Melt butter and olive oil in a large pot.
Add onions and cook over medium-low heat for 30–40 minutes, stirring occasionally, until deep golden brown.
Stir in garlic and cook for 1 minute.
Make the soup
Add wine and simmer until reduced by half.
Pour in broth and add thyme.
Simmer for 20 minutes.
Season with salt and pepper.
Prepare the ramekins
Heat oven to 425°F (220°C).
Divide soup among oven-safe bowls.
Add sautéed mushrooms.
Add cheese and croissant
Sprinkle generously with Gruyère and Parmesan.
Place a croissant partially on top of each bowl as shown in the image.
Add a little extra cheese around the croissant.
Bake
Place bowls on a baking sheet.
Bake for 10–15 minutes until cheese is bubbling and golden.
Broil for 1–2 minutes for extra browning if desired.
Serve
Garnish with fresh thyme and serve immediately.