Lazy Cooking: Bistek

Ingredients:
1/2 kilo beef (lean)
vinegar
soy sauce
brown sugar
2 cloves garlic
1 large/medium-sized onion
3 bell peppers
salt and pepper to taste

1.  Cut beef into thin slices.
2.  Mix together vinegar, soy sauce and brown sugar. The ratio of these ingredients can  be 5:3:1 (for instance, 5 tbsp of soy sauce to 3 tbsp of vinegar to 1 tbsp of brown sugar), or you can also change it according to your preference.
3. Add in roughly chopped onion and garlic. Also add in the thinly-sliced beef.
4. Mix ingredients thoroughly until all beef slices have been covered in marinade.
5. Marinate for at least an hour (or overnight, if you want to have more flavor on your bistek).
6.  After marinating, slow-cook both meat and marinade, stirring occasionally until the marinade almost dries up. Add about a teaspoon of oil to the cooking meat, then add the julienned bell peppers. Add salt and pepper to taste. Cook until the bell peppers are soft.