Preheat the oven to 200°C. Grease six tartlet tins with non-stick spray. Keep a baking sheet handy.
1 Crust Put the flour, salt, cheese, parsley and lemon zest in a food processor. Add the butter and pulse until the mixture resembles breadcrumbs.
2 Add the egg yolk and pulse until the dough starts sticking to the blade. Remove from the processor and shape into a ball. Cover with clingfilm and chill for 30 minutes.