- 115g (4oz) cold unsalted butter, cubed
- 225g (8oz) plain white flour
- a pinch of salt
- 2tbsp caster sugar
- 2tbsp ground almonds
- 1 egg, lightly beaten, plus extra to glaze
Place the butter, flour, salt, sugar and almonds in a food processor. Blitz until you have a fine breadcrumb texture but do not overwork. Add the egg and half an eggshell full of cold water and mix well, using the pulse button until the pastry forms a ball. Again, do not overwork.
Turn the pastry out of the processor and knead gently, just to bring it together. If you have doubled the mixture, divide the pastry in two. Flatten each piece of dough slightly (this makes it easier to roll when chilled) and wrap in clingfilm, then chill in the fridge for at least 20 minutes – an hour or two would be better.
Grease your tart tin. Lightly flour the work surface. Roll the pastry out so you end up with a circle about 4cm (1½in) larger in diameter than the tart tin. Carefully roll the pastry onto the rolling pin and then over the tart tin, taking care not to stretch it too much.
Immediately ease the pastry into the ring and use your thumb to gently push it into the bottom and corners; do not leave any creases in the outside edge or air between the pastry and the tin. Leave about 1cm (½in) overhanging the top edge of the ring. Trim off with a sharp knife or roll a rolling pin over the top to remove the excess. Use your thumb to squeeze up the top edge again (the pastry will shrink back a little during cooking) and pinch with your thumb and forefinger to make the edge more decorative. Using a piece of well-floured leftover pastry, push the bottom of the flan into the corners so it’s nice and flush. Chill for 30 minutes. Preheat the oven to 200 C, 400 F, gas 6.
Cut out a round piece of greaseproof paper 4cm (1½in) larger than the flan and place it inside the pastry-lined tart tin. Fill with baking beans and blind bake for 5 minutes or until the top edge is slightly brown. Remove the paper and beans, turn the oven down to 170 C, 325 F, gas 3 and cook for a further 10 minutes, until the pastry is set, but has taken no colour. Remove from the oven, brush with beaten egg (to stop the pastry getting soggy when you add the filling) and then put it back in the oven for 2 minutes to seal. Cool for a little while before adding the filling.