Your main source of calories should be beef or lamb. As both are quite expensive where I live I eat mostly ground beef. 400gr. in the morning fried in a pan as patties. 400gr. for lunch as ground beef + 100gr cheese and for dinner Steak or a couple of eggs with lots of butter. In case I need more calories I eat more butter or creme fraiche with a little honey. Sometimes I eat a little liver fried in the pan as well. Don't use any seed oils, but fry everything directly or in butter or clarified butter.