Soak the bread roll in a bowl filled with cold water, remove the roll and squeeze out the water.
Wash the bell peppers, cut off the lids (stem ends), remove the white membranes and seeds.
In a bowl combine the ground meat, bread roll, egg, onion, paprika, pine nuts, pepper and salt.
Stuff the bell peppers with the meat mixture and place the bell pepper "lids" on top.
Pour the chopped tomatoes into a casserole dish and combine it with the vegetable stock and the tomato paste. Season with salt and pepper.
Place the bell peppers upright in the casserole dish, drizzle them with 1 tablespoon of sauce and place in a 350° F oven for about 40 minutes.