Prep: slice silken tofu about 1 cm thick, chop tomatoes into small chunks, cut bell pepper into strips, and hand-tear the oyster mushrooms into thin shreds.
Heat a generous amount of oil over medium heat, lay the tofu flat, and fry until the first side is golden. Flip by sliding the tofu along the edge of the pan so it stays whole.
Push the tofu to one side, add tomatoes and oyster mushrooms to the other, and sauté until the mushrooms release liquid and the tomatoes begin to soften.
Add ½ tsp salt and ½ tsp sugar, then stir in 1 tbsp ketchup and let it caramelize briefly. Add 100 ml water and the green bell pepper strips.
Lower the heat, simmer gently for about 3 minutes so the tofu absorbs the sauce, taste and adjust sweetness, then serve hot over steamed rice.