Fresh tuna is one of the oily fish we should be eating once a week. If you prefer, cook the tuna steaks on a ridged griddle or in an oiled frying pan for 2-3 minutes on each side. This will only increase the fat content very slightly and the tuna will be firmer, drier and have more colour. Serve with boiled new potatoes in their skins. 

Preparation and cooking time: 40 minutes

Freezing: not recommended

Per serving: 224 calories, 5g fat

1⁄2 teaspoon oil
1 small onion, chopped finely
2 tuna fish steaks, each about 1.5cm (5⁄8in thick)
2 tablespoons white wine or 1 tablespoon water mixed with 1 tablespoon fresh lime juice
200g (7oz) green beans, left whole if small (about 10cm/ 4in long)
6 cherry tomatoes
1⁄2 tablespoon chopped fresh basil or 1⁄2 teaspoon dried basil
freshly ground black pepper

Heat the oil in a heavy-based small saucepan. Add the onion, cover and cook over a very low heat for 10-15 minutes until the onion is softened and golden in colour.

Preheat the oven to Gas Mark 6/electric oven 200°C/fan oven 180°C and prepare a steamer for the beans.

Cover a baking sheet with foil and place the tuna steaks in the centre. Season well with black pepper and then lift the foil at the edges to form a 'wall'. Pour the wine or water over the fish and then fold the foil to make a loose parcel. Bake for 15 minutes or until the steaks are tender.

Meanwhile, steam the beans until tender - about 8-10 minutes.

When the onion is ready, add the cherry tomatoes and cook with the lid on until the skins have split and the tomatoes are hot - 4-5 minutes. If using dried basil, add it now.

Divide the beans between two plates, spoon the tomato mixture over them and sprinkle with the fresh basil, if using. Place a tuna steak on top or by the side of each portion of vegetables.