To make the pastry flour, Combine flours, sugar in a large bowl.Add oil/ butter and rub the mixture until it forms a crumbly texture. Add vinegar, water, vanilla and bring the dough together.
Lightly knead to bring the dough together. Shape into 2 discs and wrap each in plastic wrap. Refrigerate for 30 minutes or until firm.
In a medium saucepan, combine chopped rhubarb, 1/4 cup sugar and 2 tbsp of water. Cook for 5 to 7 minutes till the rhubarb is soft and mushy.
Remove and set aside. Mix in the sliced strawberries.
Roll out 1 of the discs 4mm thick and use it to line a greased 18cm metal pie dish.
Refrigerate for 30 minutes. Roll out the remaining pastry into a square. Cut the pastry into strips depending upon the thickness you desire.
Remove the pie dish from the refrigerator and spread the almond meal, top it with sliced strawberries and rhubarb mixture.Use the pastry strips to create a lattice pattern on top of the rhubarb filling. Press the edges to seal, trimming any excess pastry.
Decorate the edges with a braided pastry giving it a neat finish. Use varieties of cutters to make a pattern.
Preheat oven to 180°C. Brush the pastry with the egg and sprinkle with the raw sugar.
Place on a large baking tray and cook for 45 minutes or until golden brown and cooked through.
Set aside for 30 minutes before serving.