Drain the excess water from the cottage cheese.
Add the egg yolk, sugar, and vanilla essence and mix.
Stir in the flour and semolina. If the mixture calls for it, you can add another tablespoon of flour. The mixture should be thick enough to shape in your hand.
Add the blueberries and gently fold in, stirring carefully.
With floured hands, shape 12 balls and place them on a floured surface.
Flatten each ball with a spoon.
Heat some oil in a frying pan, then fry the doughnuts over medium heat for about 2 minutes on each side.
Using a spatula, transfer the fried doughnuts to an absorbent towel to drain any excess oil.
Put two tablespoons of Greek yogurt on a plate, then place the doughnuts on top and sprinkle with powdered sugar and blueberries!