Pat the red snapper dry with paper towels inside and out. Using a sharp knife, make 3–4 diagonal cuts about 1/2-inch deep on each side of the fish. This helps the marinade penetrate and promotes even cooking.

Make marinade

In a bowl combine minced garlic, chopped oregano or parsley, lemon juice, orange juice, olive oil, sea salt and black pepper. Whisk until combined.

Rub the marinade all over the fish, making sure to get some into the scored cuts and the cavity. Let marinate at room temperature for 20–30 minutes (or refrigerate up to 1 hour). If refrigerated, bring back to room temperature for 15 minutes before frying.

Coating & Frying

Prepare dredge

In a wide, shallow dish, combine the all-purpose flour, cornstarch, cornmeal (if using), salt, and black pepper. Mix thoroughly so seasoning is distributed.

Heat oil

Pour vegetable oil into a large, heavy skillet or Dutch oven to a depth of about 1/2 to 1 inch (enough to shallow-fry). Heat over medium-high heat until the oil reaches about 350°F (175°C) or a small pinch of flour sizzles immediately when dropped in.

Dredge fish

Lightly shake off excess marinade from the fish. Press the fish into the flour mixture on both sides and into the scored cuts until lightly coated. Shake off any excess flour.

Fry the fish

Gently lower the fish into the hot oil. Fry on the first side for 5–7 minutes without moving, until the underside is golden brown and releases easily. Carefully flip the fish using two spatulas or tongs (supporting the body) and fry the other side for another 5–7 minutes until golden and cooked through. Total frying time will depend on fish thickness (aim for an internal temperature of 145°F/63°C at the thickest part). If the fish is large, reduce heat slightly and cook a bit longer to avoid burning the crust while finishing the interior.

Drain

Transfer the fried fish to a wire rack set over a baking sheet or to a plate lined with paper towels to drain excess oil. Keep warm in a low oven (about 200°F / 95°C) if desired while preparing the citrus finish.

Citrus Finish & Garnish

Make citrus-butter finish

In a small skillet over medium heat, melt the butter. Add a splash (about 1 tbsp) of lemon juice and 1 tsp of orange juice, and swirl to combine. Let it simmer for 30 seconds to 1 minute to slightly reduce and integrate flavors. Taste and adjust with a pinch of salt if needed.

Plate and finish

Place the fried red snapper on a serving platter. Spoon the warm citrus-butter over the fish, especially into the scored cuts, and arrange lemon wedges and orange slices around the fish. Sprinkle chopped cilantro or parsley and sliced scallions (if using) over the top.

Serve

Serve immediately while hot with extra lemon wedges on the side. Recommended accompaniments: white rice, fried plantains, or a simple green salad.