Use fresh mushrooms for the best flavor and texture. Cremini or baby bella mushrooms work beautifully. Don’t skip reserving the pasta water—it helps to loosen the sauce and helps it cling better to the rigatoni. For a lighter version, substitute the heavy cream with half-and-half or a plant-based cream alternative. Cook the onions and garlic gently to avoid burning, which can add bitterness to the sauce. For extra depth, add a splash of balsamic vinegar or a teaspoon of Dijon mustard to the sauce. Be sure to season in layers—taste as you go to avoid over or under seasoning.