Heat your grill to high.
Brush the fish with oil and season both sides of the fish with the salt and pepper. Place the fish on the grill, and grill for 3 to 4 minutes or until golden brown and slightly charred. Turn the fish over and continue grilling, for 3 to 4 minutes for medium doneness. Remove the fish from the grill and let rest 5 minutes.
Drizzle mojo over snapper and serve with grapefruit slices on the side.
1/4 cup olive oil
8 cloves roasted garlic
1 grapefruit, juiced
1/4 cup fresh orange juice
2 teaspoons grated grapefruit zest
1 teaspoon honey
2 serrano chiles, coarsely chopped
1 tablespoon chopped fresh thyme leaves
1/4 teaspoon kosher salt
Combine all of the ingredients in a blender and blend until smooth.