Chicory and caramelised onion tart

4-6

Ingredients

For the pastry

  • 120g plain flour
  • 60g unsalted butter
  • 1/2 tsp salt
  • 1 egg yolk
  • 2 tbsp cold water

For the filling

  • 20g unsalted butter
  • 2 red chicory, quartered
  • 3 sprigs thyme
  • 2 red onion, finely sliced
  • 2 tbsp brown sugar
  • 1 tbsp balsamic vinegar

For the custard filling

  • 2 medium free-range eggs, beaten
  • 300ml double cream
  • 80g Gruyère

Equally delicious served hot as a light supper or cold for lunch the next day, this chicory and caramelised onion tart is a gorgeous blend of sweet and tangy.

Method

  1. For the pastry, put the flour, butter and salt into a food processor and pulse to a breadcrumb texture. Add the egg and water, then blitz until the pastry comes together. Shape into a disc, wrap in cling film and chill for 30 minutes.
  2. Heat the oven to 210°C/485°F/gas mark 7. In a large deep saucepan, melt the butter and add the chicory, thyme and sliced onion. Fry over a medium heat for 40 minutes, stirring occasionally. Add the sugar and fry for a further ten minutes until caramelised and sticky, then turn off the heat.
  3. When the pastry has rested, lightly flour a clean surface and roll out to 2mm thickness, large enough to fit a 20cm deep-fluted tart tin. Line the tin with the pastry, making sure it sits flush to the tin. Line with foil, then baking beans. Chill in the freezer for 20 minutes.
  4. Bake the pastry for 20 minutes, then remove the beans and foil. Bake for a further five minutes and set aside. Turn the oven down to 150°C/300°F/gas mark 2. Meanwhile, in a jug, mix the eggs, cream, milk and half the Gruyère. Season the baked tart case, then pour over the custard and top with the remaining cheese. Bake in the oven for 55-60 minutes. The tart will be set, golden and cheesy Serve with chicory leaves and a classic vinaigrette.