Make sure the Fat side is on the hottest part of the grill, usually inside, use a grill that can be closed to retard flameups. Use your judgement but about 3 min per side.
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Grilling Picanha Over Charcoal
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Make sure the Fat side is on the hottest part of the grill, usually inside, use a grill that can be closed to retard flameups. Use your judgement but about 3 min per side.
source