Cook the pasta in salted water according to the instructions on the packet. Tip: Use a kettle, then it goes faster and it saves electricity.
Fry the diced onion and chopped garlic in butter until the onions are lightly brown. Clean, slice and fry the mushrooms until they are nice and brown.
Add the herb cheese, let it melt and then deglaze with cream until a creamy sauce is formed. Season to taste with the spices. Be careful with the rosemary, it has an intense taste!