Using a knife, make deep incisions in the leg. Cloves garlic are peeled and cut into slices.
Grease the top with butter. With the leg so far prepared, cover it and leave it overnight in the refrigerator or freezer.
Grill uncovered in preheated oven for 15 minutes at 392°F (200°C) - 410°F (210°C) .
Turn the oven down to 356°F (180°C) to 374°F (190°C) and bake again, uncovered 1 hour and 15 minutes, or until ready.