Thoroughly mix ground meats, onion, bread crumbs, 3 T cold water, and eggs. Flavor with salt, praprika, mustard, and parsley. Blend ingredients thoroughly. Flatten out meat mixture in the shape of a square, (8 X 20 cm). Arrange whole hard-boiled eggs in a row along the middle of the meat. Fold sides of meat pattie over the eggs. Shape meat carefully into a loaf resembling a flat bread loaf. Occasionally rinse hands in cold water to prevent sticking. Cube 2 strips bacon; cook in a Dutch oven about 2 minutes. Carefully add the vegetable oil; heat. Place meatloaf in the Dutch oven and cook until browned on all sides. Cut remaining bacon strips in half and arrange over the top of the meatloaf. Place uncovered Dutch oven in a preheated oven for about 45 minutes. While meat is baking, gradually pour hot beef broth over the top of the meatloaf; brush occasionally with pan drippings. When done remove meat to a preheated platter and keep it warm. Add quarter cup of hot water to pan and scrape all particles from the bottom. Bring to a gentle boil and add cornstarch that has been mixed with quarter cup water. Cook until bubbly and thick. Remove from heat and stir in sour cream. Reheat to warm. Season with salt and pepper if desired. Serve the sauce separately.