Steak with butter sauce and pickled onion

Ingredients:
• 2 beef tenderloin steaks
• 2 tablespoons of butter
• thyme
• Silver marinated onion OLE!
• salt & pepper

Wash the meat and dry it thoroughly. Leave them for so-called aging for about one hour before frying. Heat up the cast iron pan (it can be grill) and add oil. Put the meat on it for 5 minutes; then turn over and cook the other side. Each side should be a dark brown colour. At the end of cooking, add the butter, salt, pepper and wait a while for it to melt.
Serve with marinated onion and melted butter.