Apple and Blackberry Salt Caramel Tart

This is one of those definite successes which went down very well at a dinner party.
Makes 12 x 9cm tartlets or 1 large 27cm tart
Ingredients
Pastry
250g 00 flour
125g unsalted butter
1 egg yolk
whole milk (up to 50mls)
6 English apples such as Cox, peeled, cored and very finely sliced.
10 blackberries per tart, approximately.
Salt Caramel Sauce
150g brown sugar
150g golden …