1. Prepare the meatball mixture by combining ground beef and pork, eggs, chopped parsley, and chopped shallots. Season if necessary.
2. Once the mixture is homogeneous, add the breadcrumbs and mix again.
3. Shape the meat mixture into balls of about 120 g each using your hands.
4. Roll these meatballs in flour and cook them in a pan with peanut oil for 4 minutes, turning them often to ensure they are cooked on all sides.
5. Slice the onions and sauté them in butter until they become dark in color, then add the brown sugar and let it caramelize.
6. Sprinkle with 2 tablespoons of flour and mix.
7. Add the Liège syrup, mix, and add about 800 ml of water.
8. Bring to a boil, then add the meatballs and cook covered for 1 hour over low heat.
9. Check the consistency of the sauce and thicken if necessary with cornstarch.