Creamy Swiss Chard and Leek Gratin

Wonderfully indulgent, this might become your new favourite side dish. It’s great with roast beef or lamb, too. Hands-on time 20min. Cooking time about 30min. Serves 8

◆ 1tbsp olive oil

◆ 50g (2oz) butter

◆ 800g (1lb 12oz) leeks, cleaned and thickly sliced

◆ 150ml (¼ pint) white wine

◆ 1 garlic clove, finely chopped

◆ 1tbsp thyme leaves, plus extra small sprigs for the topping

◆ 2tbsp plain flour

◆ 500ml (17fl oz) whole milk

◆ ½tsp English mustard powder

◆ 150ml (¼ pint) double cream

◆ 100g (3½oz) Gruyère cheese or vegetarian hard cheese, grated

◆ Nutmeg, freshly grated, to taste

◆ 200g (7oz) Swiss chard (see GH Tip below)

◆ 50g (2oz) chunky breadcrumbs (use the leftover ends from the Pea and Ham Hock Crostini baguette)

1 Preheat oven to 200°C (180°C fan) mark 6. Heat the oil and half the butter in a large frying pan, add the leeks and a couple of tablespoons water and partially cover with a lid. Cook gently for 10min until beginning to soften. Remove lid, increase heat and pour in the wine. Add the garlic and the thyme leaves and bubble for a few min, until the leeks are tender. Remove from the heat.

2 Meanwhile, melt the remaining butter in a pan, add the flour and cook, stirring for 2-3min. Then, in stages, stir in the milk until smooth. Add the mustard powder and slowly bring to the boil, stirring until thickened. Stir in the cream, and slowly bring back to boil, add half of the cheese, some grated nutmeg and seasoning to taste.

3 Cut the stalks away from the chard leaves and roughly chop both. Cook the chopped stalks in a large pan of boiling water for 2min, then add the leaves and cook for a further 1min. Drain well. Toss with the leeks and transfer to a shallow baking dish about 2-2.5litre (3½-4⅓ pint) capacity. Pour over the sauce. Scatter with the remaining cheese, thyme sprigs and breadcrumbs and bake in the oven for about 15min, until bubbling and golden.

PER SERVING 326cals, 9g protein, 24g fat (14g saturates), 14g carbs (6g total sugars), 3g fibre

GH TIP If you can’t get hold of Swiss chard, use large-leaf spinach instead.