Place 8 cups flour on a clean work surface; make a well in the center. Crack eggs into the well, add butter, and pour in a little warm water. Start mixing together, adding more water if needed. Knead until dough is soft and smooth.

Cut dough into 4 pieces. Roll out one piece to 1/8-inch thickness on a floured surface. Use a glass or pastry cutter to cut circles.

Fill each dough circle with 1 teaspoon blueberries and sprinkle sugar. Fold into a half-moon shape and seal the edges. Set aside on a tea towel.