Medium and large lionfish (> 250 g) are ideal for grilling. After cutting the spines and fins of the lionfish, we remove the scales and the entrails. Salt the fish well inside and out and then, with a pastry brush, spread them with olive oil. The cooking time of each side of the fish depends on the intensity of the fire and the fish size. The fire should not be too strong because the fish will burn from the outside. Indicatively, for a fish of 250-300 g, each side does not need more than 5 minutes of grilling, while a fish of 500 g needs about 7 minutes. Beat oil with lemon (olive oil with lemon in a ratio of 2 to 1) and pour over the fishes, as soon as retired from the grill. Serve with boiled greens and add more lemon oil if needed.