Beef Steak (Bistek)

Ingredients
2 lb. flat meat, sliced into 1/4-inch pieces
2 T. calamansi juice (Filimpino citrus fruit)
3 tablespoons soy sauce
1 large onion, thinly sliced into rings
1/4 cup cooking oil
1/4 cup water
Directions
1.  Marinate the meat in calamansi juice and soy sauce and salt for at least 3 hours.
2.  Cook onion rings in oil until color turns transparent. Transfer to a serving dish, leaving the oil in the skillet.
3.  Add the meat to the skillet and cook over high heat, stirring often until tender. Transfer the meat to a serving dish.
4.  Add marinade and water to the skillet. Simmer for 10 minutes and pour over the meat and onion rings and toss together.