Blueberries can be quite expensive, but if you buy them in season, they are affordable. This recipe works equally well with blackberries. I say this is 'possibly' vegan because it depends on your margarine. Avoid ones that contain whey or vitamin D3.
Make the Pastry
Cut the margarine into small chunks, add to a small pan with the water and simmer until the margarine is all melted. Add the flour to a large bowl, stir in the salt, and then stir in the fat and water. Mix as well as you can, then tip it out onto a clean worktop and knead it a bit until all the flour is properly incorporated. Wrap in plastic film and pop in the fridge to cool down to room temperature.
Make the Filling
RInse the blueberries thoroughly and discard any that aren't looking good. Squeeze the lemon jiuce all over them in a bowl. Melt the sugar into the water in a small pan. You want a simple syrup, not a caramel. Stir the syrup into the fruit.
Assemble the Pie
Pre-heat your oven to 180°C (356°F) if it's a fan oven, or 200°C (392°F) if it's not. Butter the inside of your pie dish. Roll out a disc of pastry slightly larger diameter than you pie dish, and cut round it to make the lid. Roll out more pastry for the bottom. Press it into the tin, working it into the edge. Pour in the filling and smooth it to a single layer. Moisten the rim of the base, place the lid on top and press it down all round with your thumbs. Make some holes in the top with a fork to let the steam escape.
If you want to make a lattice top, see my cherry pie recipe, or to do the sunray effect shown here click the video link below.
Bake the Pie
Glaze the lid with beaten egg, or with soya milk if you want a vegan version. Bake for about 25 minutes, until the top is golden brown. Serve with Chantilly cream or ice cream.