Preheat the oven to 180ºC.
Cut the filo pastry into 18 even squares.
Spray the muffin tray with low calorie cooking spray, then line with one square of filo pastry.
Give the pastry a good spray of low calorie cooking spray, then place another square on top, positioning it so you have a star shape and press the pastry squares together.
Spray the filo cups with low calorie cooking spray, then place in the oven for 8-10 minutes, until the pastry is crisp and golden.
Now, make the blueberry curd filling.
Reserve a few blueberries for decoration, then place the rest in a small saucepan along with the lemon juice and sweetener. Simmer for 2-3 minutes until the blueberries begin to break down then mash or blend - it doesn't need to be completely smooth.
Whisk together the eggs, cornflour and blueberry mix in a glass bowl and place over a pan of simmering water.
Stir for 8-10 minutes until the curd thickens.
Stir in the yoghurt and allow to cool.
Divide the curd between the filo cases and pop a couple of the reserved blueberries on top to decorate. Enjoy!