Sift the flour into a large bowl, cube the butter and rub into the flour until it resembles breadcrumbs.
Stir in the sugar.
Bring together with your hands, being careful not to handle the dough too much.
Place a good spoonful of dough into the tartlet case and using your fingertips cover the base of the hole and push the dough up the side of the individual tin.
Scrunch a circle of greaseproof paper into each tartlet and fill with baking beans, put in the fridge for about 30 minutes.
Preheat the oven to 170C / gas 3.
Bake blind for about 15 minutes. If the shortbread has puffed up, prick with a fork.
Remove the beans and paper, return to the oven and bake for a further 10 minutes until a light golden colour.
Place a good dollop of blackcurrant jam in each tart and return to the oven for about 5 minutes.
Carefully remove the tarts from the tin.
Decorate with fresh blackcurrants and glaze by brush the fruit with a little more melted jam.