Put stale bread in a bowl and cover with water. Depending on the solidity of the bread amount of time it should spend in water vary. Therefore, check it every 5 min and make your decision. Bread is ready when you can squeeze it easily. Peel, cut into chunks, cover with water, and boil potatoes until soft. When potatoes are ready, mash them. Peel and dice your onion and cook it with 1 tbsp. olive oil on medium heat until soft and transparent. Ground walnuts with the help of a food processor or meat grinder. Combine squeezed bread, mashed potatoes, cooked onion, ground walnuts, squeezed garlic, and spices in a bowl. Mix until the mixture becomes even.