1Preheat oven to 350 degrees F (175 degrees C). Cut tops off of peppers, and remove seeds and membranes from inside.
2In a skillet over medium heat, saute 1 chopped onion until tender. In a large bowl, combine ground beef, sauteed onion, cooked rice and eggs. Season with parsley, salt and pepper. Mix well, and stuff into peppers. Place in a large roasting pan.
3Heat oil in a large saucepan over medium heat, Saute 2 chopped onions until soft and translucent. Stir in tomatoes. Season with peppercorns, allspice berries, ground allspice, oregano, marjoram, salt and pepper. Cook on medium heat for 15 to 20 minutes. Pour over peppers in roasting pan.
4Cover, and bake in preheated oven for 1 1/2 hours. Remove peppers, and transfer sauce to a blender, or use a hand blender. Puree sauce until smooth. Pour sauce back into pan, and reheat. Whisk in sour cream just before serving.