Ingredients
Base
- 2 tablespoons unsalted butter or olive oil (or combination)
- 3 large yellow onions, peeled, halved, and cut into ¼-inch thick slices
- Kosher salt
- Freshly ground black pepper
Mushrooms and Aromatics
- 8 ounces (225 grams) cremini mushrooms, wiped clean, trimmed, and thinly sliced
- 4 cloves garlic, crushed or minced
- ½ teaspoon dried thyme
Liquids and Thickener
- ½ cup white wine
- 2 tablespoons port or madeira wine
- 2 tablespoons all-purpose flour
- 4 cups beef broth or stock
- 1 cup water
- 1 teaspoon Worcestershire sauce
Pasta and Cheese
- 1 pound (455 grams) short pasta such as rigatoni, penne, rotini, fusilli, orecchiette, or shells
- ¼ cup (20 grams) finely grated Gruyère or Comté cheese (or more as desired)
- Chopped chives for garnish (optional)
Instructions
- Caramelize onions: Heat a large Dutch oven or pot over medium heat and melt the butter. Add the sliced onions and a big pinch of salt. Stir to coat with the melted butter, cover, and cook for 10 minutes until soft and translucent. Uncover and continue cooking over medium-low to medium heat, stirring occasionally to prevent sticking, for another 30 to 45 minutes until the onions are deeply caramelized and golden.
- Cook mushrooms and aromatics: Add the sliced mushrooms and minced garlic to the caramelized onions. Season with salt, pepper, and dried thyme. Cook, stirring occasionally, until mushrooms are softened and fragrant, about 5 minutes.
- Deglaze and thicken: Pour in the white wine and port wine, scraping up any browned bits stuck to the pot to add flavor. Stir in the flour to form a smooth paste and cook for about 1 minute to remove the raw flour taste.
- Add liquids and bring to boil: Gradually whisk in the beef broth, water, and Worcestershire sauce to avoid lumps. Increase the heat to high and bring the mixture to a boil. Taste and adjust seasoning with salt and pepper, keeping in mind the pasta will absorb much of the salt.
- Cook pasta: Stir in the short pasta. Reduce heat to medium-low, cover the pot, and let the pasta cook, stirring occasionally, until al dente and most of the liquid has absorbed, about 15 to 20 minutes depending on pasta type.
- Finish with cheese: Taste the dish and season with additional salt and pepper if needed. Stir in the grated Gruyère cheese until melted and well combined, which will thicken the sauce slightly.
- Serve: Serve immediately, topped with more grated cheese and chopped chives if desired for a fresh finish.
Notes
- Using a combination of butter and olive oil helps the onions caramelize without burning.
- Caramelizing onions takes time but is essential for developing the soup’s rich flavor.
- Choosing a short pasta shape helps it cook evenly and soak up the sauce well.
- Adjust seasoning carefully, as pasta absorbs salt during cooking.
- Gruyère cheese adds the signature nutty, melty finish, but Comté or similar cheeses can be substituted.
- Optional garnishing with chives adds a fresh, mild onion note.
- Prep Time: 15 minutes
- Cook Time: 1 hour 15 minutes
- Category: Main Course
- Method: Stovetop
- Cuisine: French
