Preheat the oven to 180°C. Combine all of the ingredients, except for the oil, in a mixing bowl. Using floured hands, shape spoonfuls of the mixture into meatballs. Heat the oil in a pan and brown the meatballs on all sides. Transfer the meatballs to an ovenproof casserole.
Mix all of the sauce ingredients together and pour over the meatballs. Season with salt and pepper.Cover and bake in the oven for 20-25 minutes. Top with a swirl of sour cream, a little smoked paprika and oregano leaves. Serve with mashed potatoes and seasonal vegetables.