Pour in the rice and stir. Season with the paprika, salt and black pepper to taste. Pour in 1 cup hot water and cook until the rice absorbs it completely.
Pour in the 2nd cup, cook until absorbed, pour in the 3rd, let it get absorbed, then pour in the 4th cup of water and the tomatoes.
Bee sure to stir periodically the whole time, to prevent the rice from burning at the bottom. Don't overcook - the filling must not become too dry. Add the finely chopped parsley and stir. Remove from the stove.
Stuff the peppers well and pour a little oil everywhere on top of them. Bake in a preheated 428°F (220 °C) oven until the peppers crisp.
The peppers and filling are going to release a little sauce in the tray - pour it over the peppers upon serving.