Place the Fate low protein all-purpose mix in a bowl. Rub in the butter and lard with your fingertips until the mixture resembles breadcrumbs.
Add a little cold water and with a pallet knife, mix to form a soft dough. Gently knead into a ball. Wrap in cling film and chill in the refrigerator for at least 30 mins.
Dust your work surface with a little Fate all-purpose mix, then roll out the pastry to 3mm thickness and use it to line a 20cm loose bottom tart tin, leaving the excess pastry to overhang the edge.
Line the pastry case with baking parchment and top with a layer of baking beads. Bake blind for 15 mins, until the pastry is dry.
Remove the baking beads and return the case to the oven for a further 5 – 10 mins until the case is a pale golden colour.
Trim the excess pastry from the edge.
To make the filling, empty the jelly pots and lemon curd into a saucepan. Heat gently until the jelly turns into a liquid consistency.
In a small bowl, mix the cornflour with 50ml of ProZero.
Add the remaining ProZero to the pan.
Warm the ProZero with the melted jellies but do not allow to boil.
Add the cornflour mix to the pan and keep stirring over a medium heat. The mixture will begin to thicken. Keep stirring and add the butter. Stir until the butter has melted and you have a glossy thick mixture.
Add the lemon juice and zest.
Pour this mixture into the cooked pastry case.
Leave to cool before placing in the fridge to set.
Dust with icing sugar before serving.
Fate low protein all-purpose mix and ProZero are foods for special medical purpose and must only be used under medical supervision.