Soak the mix in cold water for about 30 min. Rinse and boil it until semi-cooked. Peel the onion and chop it. Saute it in oil. Add the peeled tomato that you've chopped into pieces.
Stir and add the drained risotto mix. Season with salt and cook until they're left mostly in oil. Clean the peppers of their seeds by cutting off the tops and removing them.
Stuff the peppers and arrange them in an oven dish. Add any remaining filling on the sides. Pour in 1 cup water and bake in a preheated oven until the peppers are ready.