Preheat the oven to 180°C (350°F). Heat the oil in a skillet and fry the meatballs over a medium heat for 5-10 minutes, turning them frequently, until lightly browned all over. Transfer the meatballs to a large, shallow, ovenproof dish. Pour the sauce over the meatballs. Cover and bake for about 45 minutes, until the meatballs are cooked. Garnish with fresh herb sprigs and serve hot with mashed potatoes and cooked spring greens and baby carrots.