Cut the meat into thin slices lengthwise.
Add the fat to the meat, then soak the meat mixed with the fat with vinegar, oil, salt and spices.
Put the beef in a grill tray or a plate designated for grilling.
Peel the onions, cut the tomatoes in half and remove the seeds from the tomatoes, then put the tomatoes and onions in the soaking mixture.
Put the onions between the meat slices in the oven dish, then cover the meat with tomatoes.
Put the dish in the oven and bake it for twenty minutes at a temperature of 180 degrees Celsius, then reduce the oven temperature and bake the dish for an additional fifteen minutes.