In a large pan, melt butter in oil over medium heat. Cook meat in hot fat until browned on all sides.
Remove with slotted spoon to a warmed dish.
Place garlic, peppers, and onion in remaining oil, and lightly fry until onion is clear. Return meat to pan; lightly mix together. Stir in walnut pieces, and cook and stir for one minute. Stir in tomato juice, and season to taste with salt and pepper. Cover, and bring to a boil. Reduce heat, and simmer for 1 1/2 hours.