Follow the pasta package instructions to cook the pasta to al dente in boiling salted water. This process takes me about 5-7 minutes. Before you drain the pasta, make sure to reserve at least ½ cup of the pasta cooking water for later use.
In a 10-inch skillet over medium heat, melt the butter. Add the chopped onions and garlic and cook, stirring frequently for 1 minute.
Add olive oil to the pan and stir in the mushrooms. Season with 1/4 teaspoon of kosher salt, dried rosemary, and pepper. Cook the mushrooms until tender, about 5-8 minutes, stirring occasionally.
Add tomato paste to the pan and cook, stirring constantly for 30 seconds.
Stir in the wine and 4 tablespoons of the pasta water. Cook over medium heat, stirring occasionally for 1-2 minutes.
Stir in the cooked pasta and 4 tablespoons of the pasta water.
Add freshly shredded Parmesan cheese and stir until the cheese has melted into the sauce.
Transfer to a bowl and enjoy immediately.
Notes
Expert Tips
Read through the entire recipe before beginning. This healthy mushroom pasta comes together quickly. Be sure to read through the recipe and the Ingredient Notes and gather your ingredients before starting.
When cooking the mushrooms, don't overcrowd the pan: I find that a 10-inch skillet works beautifully here. You want to cook the mushrooms in a pan with a good amount of surface area. This way the mushrooms release some of the water they are holding so they brown nicely.
Cleaning Mushrooms:
To clean mushrooms: It's best not to soak mushrooms in water. Instead, give them a quick shower in running water to release the dirt. I do this by placing the mushrooms in a colander and spraying them with water until the dirt washes away.
Make sure the mushrooms are dry: Gently pat the mushrooms dry with paper towels.