Rinse the cooled meat and dry it. Stir together the oil, tomato ketchup, pepper, soy sauce and orange marmalade. Brush the meat slices with it, place them in a container and pour the remaining marinade over them. Leave the meat in the refrigerator for 3 hours.
Remove the meat slices, sprinkle with sesame seeds and grill on aluminum grill trays for about 25-half hours.
In between, brush with the marinade.