In a large pot, add vegetable oil, onion and carrot; sauté for 3 to 5 minutes. Add the ground walnut and fry for 2 to 3 minutes. Add 8 cups of pomegranate juice and salt (optional). Allow the mixture to simmer on medium-low heat for 3-4. Continuously stir to avoid the mixture sticking to the bottom of the pot.
Once the water has reduced, the oil of the walnut should be visible on the top. Add the pomegranate and sugar; stir and adjust the sweetness by adding more sugar. If you want it to be more sour, add more pomegranate molasses. Allow to simmer for addition 45 to 60 minutes.
To prepare the meatballs, in a medium sized bowl combine the minced beef, onion, salt, black pepper, cardamom powder, turmeric powder and saffron; thoroughly knead together. Mould the beef mixture into small 2cm diametre meatballs and place on a large frying pan. On medium-high heat, fry meatballs until the meat has browned; remove and keep to the side.
Add the fried meatballs to the walnut stew and cook on low heat for an additional 20 to 30 minutes.