To check if the fish is done, press on the spot right behind the head: If it feels firm and a thin knife inserted there reveals flaky flesh, you're good to go.
Recipe information
Yield
Makes 4 servings
Ingredients
Preparation
Step 1
Prepare grill for medium-high heat. Set a wire rack inside of a roasting pan; pour in water to reach just below rack. Season fish inside and out with kosher salt and pepper. Stuff with onion, parsley sprigs, oregano, and 4 scallions. Set fish on rack and cover pan with foil, leaving one corner open. Place pan on grill and cook until steam escapes from vent, 3–5 minutes. Close vent and steam fish until cooked through, 15–20 minutes.
Step 2
Meanwhile, brush half of sliced lemon and half of sliced lime with 1 tablespoon olive oil and grill, turning once, until lightly charred, about 1 minute. Chop 2 slices of grilled lemon; set remaining slice aside for serving.
Step 3
Using a sharp knife, remove all peel and white pith from whole lemon and lime; discard. Working over a medium bowl, cut between membranes to release segments into bowl. Squeeze juice from membranes into bowl; discard membranes. Mix in chopped parsley, tarragon, red pepper flakes, sugar, chopped grilled lemon, remaining scallion, and remaining 3 tablespoons olive oil; season relish with salt and pepper.
Step 4
Arrange fresh and reserved grilled citrus slices on a platter; place fish on top.
Step 5
Drizzle with walnut oil, season with sea salt and pepper, and sprinkle with poppy seeds. Serve relish alongside.p
