Preheat the barbecue 30 minutes before cooking.
Heat oil in a pan and simmer chopped garlic for 15 minutes.
Stir in chopped chillies, lime juice, and salt, then cook for 30 seconds.
Remove sauce from heat and rest for 3 hours.
Place lobster on a board and pierce the head with a sharp knife.
Split the body lengthways and remove green head parts and claw bands.
Crack the claws with a rolling pin without removing the shell.
Baste the tail meat with garlic oil and season with salt.
Grill lobster halves flesh-side down for 4 minutes.
Flip lobster and grill until the shells turn vibrant red.
Serve halves topped with sauce, coriander leaves, and lime wedges.