Rinse the octopus thoroughly under cold water. If not already done, remove the beak and cut the octopus into manageable pieces.
Tenderize the octopus by boiling it in a large pot of water for about 45-60 minutes, or until it becomes tender. Drain and let it cool.
In a large bowl, combine the minced garlic, minced ginger, soy sauce, coconut milk, vegetable oil, lemon juice, honey or brown sugar, salt, and black pepper. Mix well to create the marinade.
Add the cooked octopus pieces to the marinade, ensuring they are well coated. Cover and refrigerate for at least 1 hour, or overnight for best results.
Preheat your grill to medium-high heat.
Remove the octopus from the marinade and let any excess marinade drip off.
Grill the octopus pieces for about 3-4 minutes per side, or until they are nicely charred and heated through.
Remove the grilled octopus from the grill and let it rest for a few minutes.
Garnish with fresh cilantro or parsley if desired.
Enjoy your meal!