Cut the cleaned mushrooms into quarters. In a large pan melt butter on medium heat. Add finely chopped onion and let it cook for 3 min. Follow with mushrooms, crushed garlic and thyme. Cook for 6-10 min until all mushrooms are golden brown.
Meanwhile, cook your pasta according to your packaging instructions. Add cooked pasta into the pan with the braised mushrooms and 3 tbsp of pasta water. Mix through and add the double cream. Season with salt and pepper. Give it another mix.
Serve with shredded parmesan and freshly grated pepper.