Broad Bean Top Tart

Serves 6

For the shortcrust pastry

250g plain flour
A pinch of salt
125g cold butter, cut into small cubes
1 egg, separated
About 50ml cold milk
A knob of butter
2 large onions, or a large bunch of spring onions, finely sliced
400g broad bean tops (and/or pea shoots or spinach)
salt and freshly ground pepper
150g cheddar cheese, coarsely grated
200ml whole milk
200ml double cream
2 whole eggs plus 2 egg yolks
Salt and pepper

Start with the pastry. Put the flour, salt and butter in a food processor and pulse until the mixture has the consistency of breadcrumbs. Add the egg yolk then, with the processor running, pour in the milk in a thin stream. Watch carefully and stop adding the milk as soon as the dough comes together. Tip out onto a lightly floured board, knead a couple of times to make a smooth ball of dough, then wrap in clingfilm and chill in the fridge for half an hour.

Meanwhile, heat the butter in a frying pan over a medium heat and add the onions. Fry gently, until soft and golden brown – a good 10 minutes. Add the broad bean tops and cook for just a couple of minutes until wilted. Season well.

Preheat the oven to 170C/gas 3.

Roll out the pastry thinly and use to line a 25cm, loose-bottomed tart case. Leave the excess pastry hanging over the edge. Prick the base all over with a fork, put the tin on a baking sheet, line with greaseproof paper and baking beans, and bake for about 15 minutes. Remove the paper and beans and bake for another 10 minutes. Lightly beat the egg white, brush some of it over the hot pastry, return it to the oven and bake for a further 5 minutes. This helps to seal the pastry and prevent any filling leaking out. Trim off the excess pastry using a small, sharp knife.

Turn up the oven to 180C/gas 4.

Arrange the bean top and onion mixture over the pastry case. Scatter on the grated cheese. Combine the milk, cream, eggs and yolks, season and pour into the tart. Bake for 35-40 minutes or until lightly set and golden brown. Serve warm or cold.