This recipe would work with any white fish, but do please buy MSC-certified cod and haddock, and eat monkfish as a very occasional treat. Pollock’s much better if you can find it, or rock turbot (also known as catfish).

This is an ideal dinner party dish: it’s quick to cook; can be prepared in advance; is light but satisfying to eat and simple to make but looks pretty.

Serves 2

Ingredients
2 fillets of cod, skin removed
1 clove garlic
1/2 lemon, juice
2 spring onions
1 teaspoon chopped parsley
2 tablespoons olive oil

150g frozen peas
A small bunch of mint
1 shallot, chopped
Zest of 1/4 lemon
1 small clove garlic, crushed

About 14 cherry tomatoes, removed from the stem
1 tablespoon olive oil
pepper
1 sprig lemon thyme, leaves stripped

Preheat the oven to 180C / gas 5.

Method
Finely slice the garlic and spring onions. Tear off two large sheets of tinfoil or baking paper 40cm long. Lay one fillet in the centre of each sheet and sprinkle over the garlic, lemon juice, spring onion and parsley. Drizzle over the olive oil and crack plenty of black pepper onto each. Bring the long sides of foil or paper together and fold them over each other to form a tight seal, keeping as much space above the fish as you can. Seal the short ends in the same way, so the fish is fully sealed into its parcel. Place each parcel onto a baking sheet.

At the other end of the baking sheet huddle the tomatoes together; sprinkle the lemon thyme leaves over and crack black pepper across them.

Put the baking tray with the fish and tomatoes into the oven and cook for 15 – 18 minutes, until the fish is cooked through and the tomatoes soften (they should take about the same length of time – the tomatoes can stay in until the fish is cooked).

While they’re cooking, boil a kettle, pour it into a small saucepan and bring it back up to the boil. Tip in the peas, shallots, lemon zest, garlic and mint. Bring the water back up to the boil and bubble vigorously for two minutes. Drain the peas and tip the lot into a food processor – a stick blender is quickest, but a Magimix-style will work too. Add a teaspoon of butter, crack in some black pepper and blend until it’s a textured puree – you don’t want it too smooth. Taste and add a squeeze of lemon juice or more mint if needed.

To serve, spoon a bed of puree onto a warmed plate and transfer the fish onto it with as much of the flavouring as you can. Lay the tomatoes beside, and serve with buttery mashed potato drizzled with a tablespoon of the flavoured juice from the fish parcel.