Mix the mince with the cumin, black pepper, 1 tbsp oil and 1 tbsp water and knead well. Add 1 head finely chopped onion, knead again and put in the fridge.
Sprinkle with the flour, stir well to dissolve the flour. Season with 1 tsp salt and 1/2 tsp sugar. Bring the sauce to a boil, add the bay leaves and boil on low heat until thickened.
Shape meatballs with moistened hands, arrange them at the bottom of a tray with a nonstick coating, pour on the sauce and bake in a preheated 356°F (180 °C) oven for about 60 min.