Cook the spaghetti according to the instructions on the package.
Grate the mushrooms, slice half and chop half. Peel and chop onions and garlic. Fry all the onions and the chopped mushrooms in butter in a saucepan until the liquid boils.
Sprinkle with flour and stir. Dilute with milk and cream and cook together with stirring. Taste off with the dragon, salt, and pepper.
Fry the bacon crispy. Drain on paper towels. Fry the sliced mushroom in the bacon fat.
Mix the pasta with the sauce and add. Top with fried bacon and fried sliced mushrooms. Sprinkle with grated parmesan and parsley.