Heat olive oil in a large pan over medium heat. Add minced garlic (and red pepper flakes if using), sauté briefly until fragrant — about 30 seconds.
Add the sliced mushrooms and a pinch of salt. Cook for 3–4 minutes, stirring occasionally, until mushrooms begin to soften and release moisture.
Add the sausage, breaking it into small pieces with a spoon. Cook until the sausage browns and the mushrooms start to get a bit of color — about 5–7 minutes.
Increase heat slightly and pour in the white wine (or broth). Let it bubble and reduce until most of the liquid evaporates.
Stir in the tomato passata and chopped parsley. Reduce heat to medium-low and simmer for about 10 minutes to let the flavors meld and the sauce thicken.
Taste and adjust seasoning with salt and pepper as needed.
Toss the cooked pasta with the sauce, using a splash of reserved pasta cooking water if needed so the sauce clings well to the pasta.
Serve immediately topped with freshly grated Parmesan cheese.