Mama Chan used Annabel Langbein's crumble topping from her Free Range Cook book.

Line pie dish with store-bought puff pastry. Blind bake at 170C for 20-30 mins.
Mix tin stewed apples or stew 3 apples yourself. Add a cup or so of fresh or frozen berries, 1/2 c sugar and 2 Tbs cornflour. Pour into pie dish.
Make crumble topping by mixing:

2 c flour
1 c ground almonds
1 1/2 c brown sugar
2 c rolled oats
1 c almonds, chopped or slivered
2 tsp mixed spice
together with 250 g melted butter
Put the topping on top of the pie.
Bake at 170C for 30 mins until golden.