Marinate beef in soy sauce, lemon (or calamansi), and ground black pepper for at least 1 hour. Note: marinate overnight for best result
Heat the cooking oil in a pan then pan-fry half of the onions until the texture becomes soft. Set aside
Drain the marinade from the beef. Set it aside. Pan-fry the beef on the same pan where the onions were fried for 1 minute per side. Remove from the pan. Set aside
Add more oil if needed. Saute garlic and remaining raw onions until onion softens.
Pour the remaining marinade and water. Bring to a boil.
Add beef. Cover the pan and simmer until meat is tender. Note: Add water as needed.
Season with ground black pepper and salt as needed. Top with pan-fried onions.