In a bowl, combine garlic, oyster sauce, soy sauce, fish sauce, brown sugar, cornstarch, and black pepper. Add beef pieces and mix well. Let marinate for 1 hour or overnight for the best flavor.
Rinse and drain the rice. In a pot or rice cooker, add rice, water, tomato paste, butter, salt, and chicken bouillon powder. Cook until fluffy.
Heat a drizzle of oil in a pan over medium heat. Add beef pieces and sear for a 1 minute. Turn and sear until all sides are nicely browned and cooked through.
Optional Salad: Dress lettuce and tomato slices with a little vinegar for a fresh side.
Plate the tomato rice and top with the beef. Add lettuce and tomatoes on the side.