For the sweet pastry
- 165g/5¾oz plain flour, plus extra for dusting
- 25g/1oz ground almonds
- 120g/4¼oz chilled unsalted butter, cubed
- 55g/2oz caster sugar
- 1 free-range egg
For the custard filling
- 700ml/1¼ pint full-fat milk
- 7 free-range egg yolks
- 90g/3¼oz caster sugar
- freshly ground nutmeg
To make the pastry, stir the flour and ground almonds together in a large bowl, then add the butter and rub in with your fingertips until the mixture resembles breadcrumbs. Stir in the sugar.
Break in the egg and work it into the mixture with your fingers, bringing it together to form a soft dough.
Tip the dough onto a lightly floured work surface and shape it into a ball. Flatten with your fingers to a disc and wrap in cling film. Leave to chill in the fridge for 30 minutes.
Preheat the oven to 200C/400F/Gas 6.
Roll out the sweet pastry on a lightly floured work surface.
Using an 11cm/4½in fluted cutter, cut out twelve discs and line the muffin tray moulds with the pastry circle. The pastry should overlap the top of the moulds by a few millimetres, so that you can crimp the edges if you wish.
For the custard filling, warm the milk in a saucepan, and beat the egg yolks and sugar together in a separate bowl until pale and creamy.
Pour the milk onto the egg yolk mixture and stir well, creating little bubbles.
Transfer the custard mixture into a pouring jug with a lip, then fill each of the tart cases.
Sprinkle a small pinch of ground nutmeg into the middle of each tart.
Bake the tarts in the oven for about 25 minutes - you may need to turn the temperature down to 180C/350F/Gas 4 for the final 10 minutes. You are looking for a very slight dome on the custard, indicating that it is baked. If the custard domes too much this indicates that you have over-cooked the custard, it will have boiled, and will sink back down leaving a big dip. If this does happen you can help rescue it by removing the tarts from the oven immediately and placing the tin in cold water on a cold surface.
Cool in the tin for 30 minutes and then carefully remove from the moulds. The base of the tarts should be perfectly baked through, without having over-cooked the custard filling.