01 - Preheat a grill to high heat (about 500°F / 260°C).
02 - In a small saucepan over low heat, melt the butter. Add garlic and cook for 1 minute until fragrant. Stir in lemon juice, zest, parsley, salt, and pepper. Remove from heat.
03 - Place the oysters on the grill, flat-side up to retain their juices. Grill with the lid down for 2–3 minutes, just until the oysters start to curl at the edges.
04 - Spoon about 1 tsp of the lemon butter sauce onto each oyster. Close the grill lid and cook for another 1–2 minutes, until the butter sizzles and the oysters are just set.
05 - Carefully remove from grill using tongs. Serve immediately with lemon wedges and a sprinkle of parsley, if desired.