Rosemary & Lemon Roast Fish

Preheat the oven to 200°C (180°C fan / 400°F). Toss the thinly sliced potatoes and onion rings in a large bowl with 3 tablespoons of olive oil, half the sliced garlic, the leaves from 3 rosemary sprigs, and a generous seasoning of salt and pepper. Spread them in an even, slightly overlapping layer across a large roasting dish. Pour the white wine and 50ml of water around the edges of the dish — this creates steam that cooks the potatoes through from below. Roast for 20 minutes until the potatoes are just tender and beginning to turn golden at the edges.

While the potatoes roast, pat the fish fillets completely dry with kitchen paper — surface moisture is the enemy of crisp skin. Score the skin side of each fillet 2–3 times with a sharp knife to prevent curling during roasting. Rub both sides with olive oil and season generously with salt and pepper. Tuck a small sprig of rosemary under each fillet and place a slice of lemon on top. The scoring, drying, and seasoning all happen now so the fish is ready to go straight onto the hot potato base.

Remove the roasting dish from the oven. Scatter the cherry tomatoes and remaining garlic slices over the potato base. Lay the prepared fish fillets skin-side up directly on top of the potatoes, spacing them evenly. Arrange the lemon rounds around the fish and tuck the remaining rosemary sprigs between the fillets. Drizzle everything with the remaining olive oil and squeeze the juice of the second lemon over the top.

Return the dish to the oven and roast for 12–15 minutes, depending on the thickness of the fillets. The fish is done when the flesh flakes easily when pressed gently with a fork and the skin is golden and slightly crisp. Do not overcook — white fish goes from perfect to dry very quickly. Rest for 3 minutes before serving; this allows the juices to settle and the fish to finish cooking gently in its own heat. Serve directly from the roasting dish at the table.