Fry the rabbit legs in butter on both sides in a frying pan on low heat. If you cook it on to high heat the meat will be to dry.
In the mean while:
Clean the chanterelles and fry together with butter and parsley in a frying pan, make sure you keep them warm in a bowl when they are done.
Cook the pasta according to the instructions on the package.
Place the rabbit legs on a plate and cover them so they keep warm.
In a casserole mix the white wine, heavy cream, and the mustard together.
Put the rabbit legs in the casserole and cover them with the sauce.
Serve the rabbit together with the pasta, the sauce and the chanterelles.