For the pastry

  • 225g Plain flour
  • 125g butter cubed
  • 1 egg beaten
  • 1tbsp water
  • 30g parmesan

For the filling

  • 500g medium onions
  • knob of butter
  • 1tbsp olive oil
  • 4 large eggs
  • 300ml double cream
  • 150ml milk
  • 200g gruyere grated
  • 30g parmesan grated


  • STEP 1

    Line a 9.5-10 inch deep round loose bottom tart tin.

  • STEP 2

    To make the pastry, put the flour, butter and cheese into a food processor. Whizz until it looks like breadcrumbs. Add the egg and water and whiz until the mixture forms a ball.

    Roll out on a lightly floured work surface and line the base and sides of the flan tin with the pastry. Set aside to chill in the fridge for 30-35 minutes. Prick the base and line with baking beans.

    Pre-heat the oven to 220C / 200C Fan / Gas mark 7. Blind bake the pastry for 10 minutes. Remove the beans and bake for another 8-10 minutes until lightly golden. Place on a baking sheet.

  • STEP 3

    To make the filling. Melt the butter and oil in a frying pan. Add the onions and fry over a medium to high heat for 5 minutes. Cover with a lid and gently simmer for 20 minutes until soft and golden brown. Spread onto the base of the tart.

    Beat the eggs in a bowl. Add the cream and milk and season. Add the gruyere cheese, then pour into the case. Sprinkle with the parmesan.

  • STEP 4

    Reduce the oven to 180C / 160C Fan / Gas mark 4. Bake for 30-35 minutes until lightly golden on top and set in the middle.

Annabel's Family Cookbook (£20, Ebury Press) is available to buy now.
Annabel's Family Cookbook (Ebury Press) is available to buy now.

Annabel’s Family Cookbook (Ebury Press) is filled with cooking inspiration for the whole family and available to buy from 13 March. Visit