In a small bowl, add the kecap manis, oyster sauce, tomato sauce, sambal, fish sauce, soy sauce, sugar and pepper. Mix until combined into a smooth sauce.
4 tbsp kecap manis / sweet soy sauce, 2 tbsp oyster sauce, 2 tbsp tomato sauce / ketchup, 2 tbsp sambal, 1 tbsp soy sauce, 1 tbsp fish sauce, ½ tsp sugar, ¼ tsp white pepper