Clean and remove the black cabbage from the stems. Chop the onion and finely chop the garlic. Clean the mushrooms and cut into slices or quarters.
Fry the onion and garlic in olive oil. Add black cabbage and fry for 3 minutes. Add mushrooms. Fry everything for another 3 minutes. Pour in the cream and simmer over low heat. Season the black cabbage with salt and pepper. If necessary, thicken the sauce with a sauce thickener.
In the meantime, cook the pasta according to the instructions on the packet.
Serve black cabbage with spaghetti and refine with parmesan if you like.