Mix the livers with 3 1/3 tbsp (50 ml) of oil or olive oil and the spices to taste. Heat up a grill and grease the elements. Turn the livers over several times on both sides to cook them well.
Then put the onions, cut into thick circles, on the grill. As soon as they brown evenly, smother them in a glass pot with a lid and add a little oil, salt and pepper.