Preheat oven to 200ºC (180ºC fan assisted) 400ºF/Gas M 6.
Roll out pastry large enough to form a 35cm disc and lay on a baking sheet. Brush all round edges lightly with water and fold over 2-3cm all round to form an edge.
Combine the apple slices with juice, sugar and ground almonds and place on tart base. Scatter with flaked almonds and bake for 20 minutes or until pastry is golden brown and apples just cooked.
Scatter with lemon zest and if desired a few mint leaves before serving.
