To make the pastry, put the gluten free flour, lactose free butter and cayenne pepper into a food processor, then whizz into fine breadcrumbs. sprinkle the egg and water mixture onto the flour, then pulse again until the mixture begins to come together.
Tip the mixture onto a board and gently squeeze the pastry until it begins to come together in a ball, adding more water if it feels dry.
Heat oven to 190C/fan 170C/gas 5. roll the pastry into a large a4-sized rectangle, roughly 20 x 30cm. Brush the sheet with the beaten egg and cut in half widthways.
Sprinkle one half with the Parmesan and the second half with poppy and caraway seeds. lightly run the rolling pin across the top to press the cheese and the seeds into the pastry.
Cut each half into 12-15 sticks. arrange on a baking sheet and chill for 10 mins. Bake for 8-10 mins until golden brown, then cool for 5 mins before lifting onto a wire rack.