
In a bowl, combine fish sauce, brown sugar, garlic, and pepper.
Add meat and massage with the marinade to coat fully. Cover and marinate in the refrigerator for about 2 hours or overnight. Drain beef from the marinade.
In a pan over medium heat, add meat in a single layer and water. Simmer until tender and most of the liquid is absorbed.
Add oil and pan-fry the meat, turning once or twice, until lightly browned and cooked. Serve hot.