Bring milk to a boil and stir in lemon juice to curdle.
Strain the mixture through a muslin-lined sieve overnight and refrigerate the solid curds.
Rub flour, salt, butter, and lard together into fine breadcrumbs.
Add water to form a dough and knead briefly until smooth.
Wrap dough in cling film and rest in the fridge for 30 minutes.
Roll pastry to 0.5cm thickness and line a 20cm tart tin.
Prick the base and rest in the fridge for 10 minutes.
Preheat oven to 200°C.
Blind bake the pastry case for 15 minutes with weights, then 5 minutes without.
Mix softened butter, rosewater, curds, eggs, and currants until combined.
Pour filling into the case and bake for 20-30 minutes until set.
Allow to cool before slicing into wedges to serve.