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Caramelized Onion and Mushroom Pasta with Creamy Sauce - Cozy, Savory, and Weeknight-Friendly

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Prep Time 15 minutes
Cook Time 30 minutes
Total Time 45 minutes
Servings: 4 servings
Ingredients Method

Ingredients
  

  • Pasta: 12 oz fettuccine, tagliatelle, or rigatoni
  • Yellow onions: 2 large, thinly sliced
  • Mushrooms: 12–16 oz cremini or baby bella, sliced
  • Garlic: 3–4 cloves, minced
  • Butter: 2 tbsp
  • Olive oil: 2–3 tbsp
  • Dry white wine or broth: 1/2 cup (for deglazing)
  • Heavy cream: 3/4 cup (or half-and-half for lighter)
  • Parmesan: 1/2 cup freshly grated, plus more to serve
  • Fresh thyme or rosemary: 1–2 tsp chopped (optional but great)
  • Red pepper flakes: Pinch (optional)
  • Lemon: 1 (zest and 1–2 tsp juice)
  • Salt and black pepper
  • Fresh parsley: Small handful, chopped (for garnish)

Method
 

  1. Slice and prep. Thinly slice the onions and mushrooms. Mince the garlic. Grate the Parmesan. Bring a large pot of salted water to a boil.
  2. Start the onions. In a wide skillet, heat 1 tbsp olive oil and 1 tbsp butter over medium-low. Add onions with a pinch of salt. Cook 25–35 minutes, stirring occasionally, until deep golden and jammy. If they brown too fast, lower the heat and add a splash of water.
  3. Sear the mushrooms. Transfer onions to a bowl. In the same pan, add 1 tbsp olive oil and the mushrooms in an even layer. Cook undisturbed 3–4 minutes to brown, then stir and cook until they release moisture and concentrate. Season with salt and pepper.
  4. Build flavor. Add the garlic and herbs; cook 30 seconds until fragrant. Return onions to the pan. Add red pepper flakes if using.
  5. Deglaze. Pour in white wine or broth. Scrape up browned bits and reduce by half, 2–3 minutes, until syrupy.
  6. Boil pasta. Cook pasta until just shy of al dente. Reserve 1 cup pasta water before draining.
  7. Creamy sauce time. Reduce heat to low. Stir in cream and 1/3–1/2 cup pasta water. Simmer gently 1–2 minutes to thicken slightly. Add lemon zest and juice to brighten.
  8. Marry the pasta and sauce. Add drained pasta to the skillet. Toss with tongs, sprinkling in Parmesan to melt and emulsify. Add more pasta water as needed for a glossy, silky sauce that coats the noodles.
  9. Finish and taste. Stir in remaining butter for extra shine. Adjust salt, pepper, and acidity. Garnish with parsley and extra Parmesan. Serve hot.