Add the flour, butter, salt and shortening to a food mixer, and mix on low speed until you reach a breadcrumb consistency with a few lumps of butter that look like the size of peas.
Once at the pea' stage, slowly add the water until the dough starts to pull together into clumps but isn't in one big ball. Tip it out onto a work surface, wrap in cling film and chill in the fridge for a few hours or overnight.
Peel & slice the apples into chunks, and add to a pan with the sugar, corn flour and 2 tablespoons water. Stew for about 5-6m on a medium heat until slightly soft. Put in the fridge to cool.
Roll out your dough into a circle, it should be the thickness of a pound coin. Lay it over the pie plate and crimp the edges to create a crust.
Add in the chilled apple and top with chopped strawberries.
Next make the crumble, work the flour, sugar and butter together until you have small lumps. Add in the oats & chopped nuts. Sprinkle this on top of the pumble.