Use a 23-cm flan tin with a loose base. Combine the flour, icing sugar, orange rind and baking powder in a large bowl. Add oil and 2 tbsp orange juice; stir to combine. Flour hands and work surface and knead dough to form a ball. Flatten into a disc and wrap in cling wrap. Chill for 30 minutes.
Preheat oven to 180°C. Press dough into the tin to line base and side. Prick base several times with a fork. Line with baking paper; fill with dried beans or rice. Bake case for 15 minutes; remove paper and beans. Bake a further 10 minutes or until golden. Cool on a wire rack.
Combine the blueberries, the remaining orange juice, 6 tbsp sugar, the pepper and the nutmeg in a pan; bring to the boil. Reduce heat; simmer for 5 minutes.
Combine the remaining 2 tbsp sugar and the cornflour. Add to the berries and cook for 2 minutes or until the berry mixture is thick.
Cool the blueberry mixture to room temperature, then spoon into the baked shell. Chill the tart for 1 hour before serving.