Onion tart from Alsace | Daily Mail Online

Is there anything more gorgeous than lots of onions cooked with butter for up to an hour? In this recipe, they’re simply combined in a shortcrust pastry case with egg yolks and cream then baked. This is the sort of tart the French do so well. Go easy with the nutmeg – a soupçon is enough but still makes a difference.

SERVES 4-6

PASTRY

225g plain flour, plus extra for rolling

½ tsp salt

130g cold unsalted butter, cubed

1 egg yolk

1-2 tbsp ice-cold water

FILLING

60g butter

800g onions, finely sliced

200ml double cream

4 egg yolks, beaten

a rasp or 2 of freshly grated nutmeg

salt and black pepper

• For the pastry, put the flour, salt and butter in a food processor and pulse until you have a mixture resembling breadcrumbs. Transfer it to a bowl, add the egg yolk and just enough of the water to bring the dough together; too much water makes tough pastry.
• Turn the dough out on to a lightly floured board. Roll it out to a circle about 26cm in diameter and use it to line a 23cm loose-bottomed flan tin. Cover and refrigerate for 30-40 minutes.
• While the pastry is chilling, make the tart filling. Melt the butter in a large pan and add the onions, stirring to coat them in butter. Cover the pan with a lid and cook the onions over a low heat for 30-45 minutes until they are meltingly soft and sweet, checking occasionally to stir.
• Take the pan off the heat then stir in the cream and the egg yolks. Season with the nutmeg, salt and pepper. Set aside. Preheat the oven to 200C/180C fan. Line the pastry case with grease-proof paper and baking beans then bake for about 10 minutes. Remove the beans and paper then put the pastry back into the oven for 3-4 minutes to dry out the base a little. Turn the oven down to 170C/150C fan.
• Pour the onion mixture into the pastry and bake for 20-25 minutes or until just set. Serve warm or at room temperature with a green salad.