Brush off any dirt from the mushrooms with a pastry brush and tear them in half.
Heat the butter in a very hot frying pan and add the mushrooms. Let them fry fast, tossing once or twice, then add the garlic and red chilli pepper with a pinch of salt (it is very important to season the mushrooms slightly, as it really brings out the flavor). Then add the cognac and continue to fry for 4 or 5 minutes, tossing regularly.
Meanwhile, cook the pasta in boiling, salted water until al dente. Drain and add to the mushrooms, with the grated cheese (Västerbotten or parmesan). Toss gently, coating the pasta with the mushrooms and their flavor.
Season with sea salt and fresh ground pepper and sprinkle some fresh parsley.