Melt butter in a frying pan or a pan with a thick bottom and a cover.
Fry onions, garlic, parsley, chili pepper, thyme, prosciutto on average fire.
Fry during 7-10 minutes till onion becomes translucent. Then add white wine and allow it to be evaporated on a half.
Put your clams on the frying pan and close the cover. It will take you 10. It’s exactly while there is a time for cooking your spaghetti. As soon as cockleshells have opened add tomatoes and cream.
Stew a minute more just only to heat up cream, as cooking has been finished already. It only remains to mix sauce with spaghetti.
Now it is ready!