# What You'll Need:
→ Pasta
01 - 12 oz rigatoni or penne
→ Onions
02 - 3 large yellow onions, thinly sliced
03 - 2 tbsp unsalted butter
04 - 1 tbsp extra-virgin olive oil
05 - 1/2 tsp fine salt
06 - 1/4 tsp freshly ground black pepper
07 - 1 tsp granulated sugar
08 - 2 cloves garlic, minced
09 - 1 tsp fresh thyme leaves (or 1/2 tsp dried)
→ Sauce & Assembly
10 - 1/2 cup dry white wine
11 - 2 cups vegetable broth
12 - 2 tsp Worcestershire sauce
13 - 1 tbsp all-purpose flour
14 - 1 cup heavy cream
15 - 1 1/2 cups grated Gruyère cheese, divided
16 - 1/2 cup grated Parmesan cheese
17 - 1 tbsp chopped fresh parsley (for garnish)
# How to Make It:
01 - Preheat oven to 400°F. Lightly grease a 9x13-inch baking dish and set aside.
02 - Bring a large pot of generously salted water to a boil. Add pasta and cook until just shy of al dente—typically 1–2 minutes less than package directions. Drain and reserve.
03 - In a large skillet over medium heat, melt butter with olive oil. Add sliced onions, salt, pepper and sugar. Cook, stirring frequently, until onions are deeply golden and caramelized, about 25–30 minutes.
04 - Stir in minced garlic and thyme and sauté for about 1 minute, until fragrant.
05 - Sprinkle in the flour and cook for 1 minute. Pour in the white wine, scraping up any fond from the skillet, and simmer for 2 minutes to reduce slightly.
06 - Add the vegetable broth and Worcestershire sauce, bring to a gentle simmer and cook 2–3 minutes to meld flavors.
07 - Reduce heat to low, stir in the heavy cream and 1 cup of the Gruyère until the cheese melts and the sauce is smooth. Taste and adjust seasoning.
08 - Add the drained pasta and the Parmesan to the skillet, tossing to coat evenly in the sauce.
09 - Transfer the pasta mixture to the prepared baking dish and sprinkle the remaining 1/2 cup Gruyère evenly over the top.
10 - Bake in the preheated oven for 20–25 minutes, until the top is bubbly and golden brown.
11 - Allow to rest 5 minutes after baking, then garnish with chopped parsley and serve.
