Ingredients

• 1/4 small white onion, finely chopped
• 1/2 cup finely chopped fresh cilantro
• 1/4 cup fresh lime juice
• 1 teaspoon grated peeled ginger
• 1 teaspoon sugar
• 1/2 cup finely chopped fresh mint plus 4 sprigs for stuffing
• 2 red chiles (such as Fresno or serrano), with seeds, thinly sliced, divided
• 1/3 cup plus 1 tablespoon vegetable oil
• Kosher salt
• 2 whole branzino or small red snapper, cleaned
• 1 lime, thinly sliced

Instructions

1. Prepare grill for medium-high heat. Mix onion, cilantro, lime juice, ginger, sugar, chopped mint, half of chiles, and 1/3 cup oil in a medium bowl; season with salt. Set relish aside.
2. Season inside of fish with salt. Stuff with mint sprigs, lime slices, and remaining chiles; tie with kitchen twine. Drizzle with remaining 1 tablespoon oil; season with salt. Grill fish until skin is crisp and flesh is flaky and opaque down to the bone, about 5 minutes per side. (If a small knife slides easily through the thickest part of flesh, the fish is done.) Serve with relish.
3. DO AHEAD: Fish can be stuffed and tied and relish can be made 6 hours ahead. Cover separately and chill.