Step 1

To make the crumble, use an electric mixer to beat the soften butter with the sugar until creamy.

Step 2

Add the flour and lemon zest, and use your hands to make a mixture that resembles crumbles.

Step 3

Add half of this mixture to a pie tin, and press down and up the tin walls well to create a crust.

Step 4

Cover the crust with non-stick baking paper, and fill it up with dry pulses or ceramic baking beans.

Step 5

Bake in the preheated oven at 180 degrees Celsius (350 Fahrenheit) for 15 minutes, then remove the paper and pulses and continue to bake for a further 5 minutes until golden.

Step 6

To make the filling, mix the blueberries with sugar, cornflour and lemon juice.

Step 7

Transfer the filling onto the baked crust, and top with the remaining crumble mixture.

Step 8

Bake for a further 15 minutes until the top is golden.

Step 9

Cool down completely before slicing.