• 1kg white potatoes, such as Maris Piper or King Edward
• 2 lemons, sliced into rounds
• 1 red onion, thickly sliced
• 1 bunch fresh tarragon
• 4 garlic cloves, lightly crushed
• 2 tbsp extra virgin olive oil
• 1 large knob butter, softened
• 1 whole sea bream, sea bass or similar white fish, about 1kg, scaled and gutted
• Salt and freshly ground black pepper

Peel and slice the potatoes into rounds about 1cm thick. Arrange in a large roasting tray with the lemon, onion, half the tarragon and garlic. Drizzle with olive oil and season well.

Cover loosely with baking parchment and roast for about 30 minutes, turning occasionally, until tender.

Slash the fish several times on each side and lay it over the potatoes.

Mix the remaining chopped tarragon with the butter and seasoning and spread over the fish.

Increase the oven temperature to 200°C fan and roast for about 20 minutes, until the fish is cooked through.

Serve directly from the tray.