Start by cooking the mushroom and onion with a bit of oil, over medium heat for about 8-10 minutes, until browned and softened.
Add the zucchini and sauté for 2-3 minutes to give it some color.
Add the garlic and basil and cook for about a minute.
Add the pasta, salt, and water and bring it to a boil. Press the noodles down into the pot as they start to soften. Cook the noodles for 8-12 minutes, depending on the package instructions. If your pot gets too dry, add more water. Stir the noodles every 30-60 seconds for the first few minutes so that they don't stick together. Shorter pasta shapes won't need as much stirring.
Once the pasta has cooked and most of the water is gone, add the cheese and the cream. Remove from heat and stir well.
Add the lemon juice and stir. Season with salt and pepper and then serve while hot.
Video
Notes
Substitutions
Noodles: You can use whatever pasta you prefer for this recipe, even short pasta shapes like gemelli or farfalle. Pasta cooking time varies, but the water-to-pasta ratio should still be about the same - 1 cup of water to 2 oz. of pasta.
Heavy cream: Try milk or half and half instead for a less rich and creamy sauce.
Variations
Want to add protein? Cook chicken or sausage in the pot with the onions or mushrooms.
Want to keep it vegetarian but add protein? Add a vegan sausage or chickpeas when you add the pasta.
Want different vegetables? Try green peas or yellow squash. Add asparagus, olives, or chopped bell peppers in the last few minutes.
Want different cheese? Instead of Parmesan, try Asiago, Manchego, or Pecorino Romano.
Tips
Sauté to start: sauteing the onion, mushrooms, and garlic at the beginning brings more depth of flavor out of those ingredients than you would get if you simply boiled everything together. It's worth the extra time and still keeps this a one-pot pasta recipe.
Al dente: I like to cook the pasta to al dente for the best texture. Once you add the cheese and cream, mix the dish, and then finally serve it, the pasta will have cooked a bit more.
Season throughout: seasoning as you go will build flavor. I like to season when I cook the mushrooms and onions, again when I add the pasta and water, and then again before serving the dish.