Put the ground almonds into a food processor and pulse them until you have achieved a very fine texture, similar to almond flour. Then tip in the caster sugar, salt, butter and vanilla and pulse until the mixture starts to resemble fine breadcrumbs. Add the egg yolk and keep pulsing until the mixture just comes together. If the mixture still looks a bit dry after you’ve pulsed it a few times, then carefully scrape down the sides of the bowl and sprinkle the tablespoon of water over the dry parts, then pulse again.
Tip the mixture onto a work surface and squidge together into a ball. It is ready for use, or you can keep the pastry wrapped in cling film in the fridge for up to a week.
When rolling the pastry out, it helps to start by flattening it out with a wooden spoon, spatula or with your fingers.
Use as required – I bake mine in an oven that has been