Cook the rice with the turmeric until cooked. In the meantime, dice the onion and cut the zucchini into very thin slices and cut them in half. Drain the corn and, if using canned mushrooms, this too.
Fry the onions in a little oil in a large pan, as soon as they are translucent, add the zucchini and fry well. Now fry the mushroom slices, then add the tomato pieces and a good 1 tablespoon of tomato paste, stir everything and let it boil briefly. Mix in the corn, let it get hot and season well with oregano. Mix in the finished rice, season everything with salt and pepper and serve.