From inside of fish, cut through spine to break at head and tail. Starting at head with sharp, fine knife, slide knife under ribs down each side of fish, then, holding head end of spine, pull out spine with attached rib bones.

Cut out remaining row of bones that run down centre from head to tail, and trim edges of belly, removing any bones. Feel for and remove any bones that were missed.

Open out and flatten fish, skin side down, on work surface and sprinkle with 1/4 tsp/1 mL of the salt and pinch of the white pepper.

Place bread crumbs in large bowl. In skillet, melt butter over medium heat; fry shallots, celery, garlic and pinch of the salt until vegetables are softened, about 4 minutes. Scrape into bowl; add chives, parsley, celery leaves, tarragon, lemon rind and juice, nutmeg and pinch of the white pepper and toss to thoroughly mix.

Stir in egg yolk until fully incorporated. Spoon bread-crumb mixture evenly over opened fish, then close around mixture.

With toothpicks, fasten edges together at 1-1/2-inch/4 cm intervals; lace kitchen string back and forth around toothpicks to secure. Brush melted butter all over skin; sprinkle with generous pinch of the salt and black pepper.

Grill over medium-high heat, turning once, until thermometer inserted in centre of stuffing registers 155F/67C, about 20 minutes.

Makes 4 servings.