Preheat the oven to 170°C. Line a baking sheet with baking paper and grease with nonstick spray.
1. Crust Put the flour, salt, butter, white sugar and lemon zest in a food processor and pulse until the mixture looks like breadcrumbs.
2. Add the lemon juice and 30ml (2T) of the water. Pulse until a dough starts to form (add a little more water if needed).