? kilo beef sirloin (cut into 3 " strips)
2 tablespoons soy sauce
2 tablespoons calamansi juice
1 teaspoon salt
1 teaspoon pepper
cooking oil
1 big red onion (sliced thinly to make rings)

1. Marinate beef in soy sauce, calamansi, salt & pepper for 30 minutes.
2. In a pan, heat oil and stir-fry beef until cooked and tender. Set aside
3. Saute onion rings in oil.
4. Serve beef in a platter topped with onion rings.