Boil a large pot of water.Season it with a lot of salt.(the water should taste as salty as sea water).Add the spaghetti.Cook el dente.Drain and reserve ¼ cup of pasta cooking water.
Meanwhile ,heat a cast iron pan or a non stick pan - add butter and the olive oil.
Once the butter melts, Add sliced mushrooms.Do not move the mushrooms in the pan for atleast 2 minutes.This will help in caramalisation.
Add the garlic, give the mushrooms a mix and cook for another 5 minutes till the mushrooms wilt.
Sprinkle over the dried herbs and chilli flakes.
Add ¼ cup of pasta water.Add the cooked pasta.
Sprinkle about ¼ cup of parmesan(optional).Mix toghther.