Put the calamansi juice, sugar, and soy sauce all together in a bowl.
Mix with a wire whisk and make sure the sugar is properly dissolved.
Place the beef in another bowl and pour calamansi mixture onto the beef. Mix well. Set aside.
Add oil in pre-heated pan. Put your beef cuts into the pan and fry.
Season with salt and pepper. Set aside.
In the same pan, pour the sauce you prepared earlier. Bring to a boil.
Happy cooking, Foodies!