- For the pastry:
You need a loose-bottomed, 24cm fluted tart tin. Make the pastry in a food processor. Mix the flour, butter and sugar to breadcrumb stage, then add the egg yolk and water and mix until the dough comes together. Roll out on a floured worktop to 5mm thick, a little bit bigger than the base of the tin.
Line the tin, then use your fingers to press the pastry into the corners and about 1cm up the sides to create a small lip around the edge. Cover with clingfilm and leave in the fridge for at least 30 minutes.
Heat the oven to 190°C/gas 5.
Remove the clingfilm and prick the pastry base all over lightly with a fork. Line with greaseproof paper and baking beans or lentils, and bake for 15 minutes. Remove the baking beans and paper and return to the oven for 3 to 4 minutes to dry out the base without colouring.
Make the filling. Toast the flaked almonds in a dry frying pan over medium-high heat for 2 to 3 minutes until a light golden brown, keeping a close eye on them. Tip into a bowl.
Put the butter, sugar and milk in the frying pan over medium heat. When the sugar has dissolved and the butter melted, bring up to a boil and boil for 1 minute. Add the toasted almond slivers and mix well before turning into the pastry case.
Bake for 15 to 20 minutes until a rich golden brown. Remove from the oven and allow to cool before serving.
Serve warm or cold.