Start by cleaning and trimming your 2-pound fresh whole yellowtail snapper. Rinse the fish under cold water, then pat dry with paper towels. Place the snapper in a shallow baking pan that allows for even marinating.

In a medium bowl, combine 2 minced garlic cloves, ½ finely minced scotch bonnet pepper, 1 teaspoon of kosher salt, and ½ teaspoon of black pepper. Add in 4 chopped scallions, 1 thinly sliced shallot, ½ cup of fresh lime juice, and 2 tablespoons of olive oil. Mix thoroughly until all ingredients are well blended.

Fill the cavity of the snapper with 6 sprigs of fresh thyme and ½ cup of thinly sliced onion. Pour the marinade over the fish, ensuring it coats every surface. Cover the baking pan with plastic wrap and refrigerate for 1 hour.

In a mixing bowl, whisk together 1 large egg yolk, 1 teaspoon of Dijon mustard, and 1 minced garlic clove. Gradually drizzle in 1 cup of vegetable oil while whisking continuously until the mixture thickens and emulsifies. Mix in a splash of lime juice and refrigerate.

Preheat your grill to 450°F. Use a fish basket for easy handling. Place the marinated snapper on the grill and cook for about 10-12 minutes on each side until the skin is charred and the flesh is flaky.

Once cooked, transfer the fish to a serving platter. Garnish with sprigs of fresh parsley, chopped scallions, and lime wedges.