Ingredients
2 tablespoons olive oil (1 for onions, 1 for mushrooms/spinach)
3 large yellow onions, sliced
¼ teaspoon salt (plus a pinch for mushrooms)
1 tablespoon balsamic vinegar
10 oz mushrooms, sliced
6 oz fresh spinach
1 cup half-and-half
1 cup parmesan cheese, shredded (â…” cup for sauce, more for serving)
8 oz farfalle pasta
Instructions
1. Caramelize the Onions — Heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Add the sliced onions and cook for about 10 minutes, stirring constantly until they start to brown. Reduce heat to medium and continue cooking for another 10 minutes, stirring frequently. Add a pinch of salt. Continue cooking on medium or low heat for 10 more minutes, stirring occasionally to prevent sticking or burning — 30 minutes total. Remove from heat, add the balsamic vinegar, stir to deglaze the pan and coat the onions. Transfer caramelized onions to a plate.
2. Cook Mushrooms and Spinach — In the same skillet, heat the remaining 1 tablespoon of olive oil over medium heat. Add the sliced mushrooms and a pinch of salt. Cook for about 5 minutes, stirring occasionally, until the mushrooms are soft. Add the fresh spinach and stir on low heat just until it begins to wilt.
3. Make the Creamy Sauce — Pour the half-and-half into the skillet with the mushrooms and spinach. Bring to a quick boil, then immediately reduce to a simmer. Add ⅔ cup of the shredded Parmesan cheese and ¼ teaspoon salt. Stir continuously while the sauce simmers until the cheese is fully melted and the sauce is smooth.
4. Combine with Pasta — Add the caramelized onions back into the skillet with the creamy sauce. Meanwhile, cook the farfalle pasta according to package directions. Drain the pasta and add it to the skillet with the sauce. Stir on low heat for a couple of minutes to reheat everything and coat the pasta evenly. If the sauce is too thick, add a small amount of half-and-half to thin it out. If too thin, add a bit more shredded Parmesan while the sauce simmers.
5. Serve — Serve hot with extra shredded Parmesan cheese sprinkled on top.
Notes
Patience is key for caramelized onions — Don’t rush the caramelization process. The low and slow cooking over 30 minutes is what develops the deep, sweet flavor. Stir occasionally to prevent burning.
Don’t overcrowd the pan — When cooking mushrooms, make sure they have enough space in the skillet. Overcrowding will cause them to steam rather than brown, affecting texture and flavor.
Reserve pasta water — Before draining the pasta, save about a cup of the starchy pasta water to adjust the consistency of your sauce if it becomes too thick.
Freshly grated Parmesan — Use freshly grated Parmesan rather than pre-shredded for the best flavor and melting quality.
Half-and-half substitute: Mix ½ cup heavy cream with ½ cup milk for a similar richness and consistency.
Make ahead: Prepare the caramelized onions, mushrooms, spinach, and sauce ahead of time. Store separately in the refrigerator and cook pasta fresh when ready to serve.
Storage: Store leftovers in an airtight container for up to 3 days. Reheat gently in a skillet over low heat with a splash of milk or half-and-half to loosen the sauce.
Variations: Add grilled chicken, shrimp, or Italian sausage for a heartier meal. Substitute spinach with kale, arugula, or Swiss chard. Deglaze the pan with a splash of white wine before adding the half-and-half for a wine-infused sauce.
- Prep Time: 10
- Cook Time: 45
- Category: Dinner
- Method: Stovetop
- Cuisine: Italian
- Diet: Vegetarian