In a medium saucepan, warm 3 tablespoons of olive oil.

Add diced onion and cook for approximately 3 minutes.

Add minced garlic, cumin, oregano, salt, and pepper.

Cook for an additional 2 minutes.

Add orange juice, lime juice, and dark rum to the saucepan.

Bring the mixture to a boil, then reduce heat and simmer for 10 minutes.

Remove from heat and allow it to cool.

Rinse the snapper under cold running water.

With a sharp knife, make three 2-inch slits on each side of the fish.

Place the fish in a glass baking dish and pour the cooled sauce over the snapper, ensuring it reaches into the scored flesh.

Cover and let it marinate in the refrigerator for 1 hour.

Remove the fish from the marinade and pat it dry with a paper towel.

If desired, use a fish basket for easy grilling.

Drizzle the fish with the remaining olive oil and place it on the preheated grill.

Grill until the first side is brown and crisp (approximately 5 to 7 minutes), basting occasionally with the rum sauce.

Carefully turn the fish and continue cooking.

Baste the snapper with the rum sauce until cooked through, another 5 to 7 minutes.

Serve the Rum-Glazed Barbecue Snapper with fried plantains and a bright bib lettuce salad for a taste of the sunny seaside.