Using a sharp knife or kitchen shears, carefully cut lengthwise through the top shell of each lobster tail, stopping just before the fin. Gently pull the shell apart and slice the meat along the same line. Cut through the underside shell and loosen the meat so it rests on top for even grilling.

Season:

Lightly brush the lobster meat with oil and season evenly with salt, garlic powder, and black pepper.

Make the Butter Sauce:

In a bowl, whisk together melted butter, garlic, mustard, parsley, chili flakes, cayenne, and lemon juice until well combined. Set aside for basting and dipping.

Preheat the Grill:

Heat the grill to medium-high heat, about 400°F. Clean and lightly oil the grates.

Grill the Lobster:

Place lobster tails flesh-side down on the grill. Cook for 2–3 minutes until the meat turns opaque and the shells brighten in color. Flip the tails, baste generously with the butter sauce, and cook for another 1–2 minutes until the internal temperature reaches 145°F.

Serve:

Remove from the grill and serve immediately with extra garlic butter on the side for dipping.