Cook the rice in boiling salted water for 15-20 minutes. Peel and finely chop the onion. Wash, clean and roughly chop the mushrooms. Heat oil in a pan. Sauté onion and mushrooms.
Flavour with paprika powder. In the meantime wash herbs, dab dry and chop finely. Drain the rice and add to the mushrooms with the herbs. Clean the bell peppers, cutting the lid off the red pod. Cut yellow and green pods into pieces. Mix half of the paprika pieces with the rice. Fill the red pods with half of the vegetable rice. Heat the vegetable stock in a small pot. Put the stuffed peppers in and cook covered for about 15 minutes. After 5 minutes add remaining vegetable cubes.
Fill the red pods with half of the vegetable rice. Heat the vegetable stock in a small pot. Put the stuffed peppers in and cook covered for about 15 minutes. After 5 minutes add remaining vegetable cubes. Stir the sauce thickener in sour cream until smooth and thicken the vegetable stock with it. Fold the rest of the rice into the vegetables and heat up. Season again and arrange on a plate