Roll each dough ball into a long teardrop shape, keeping the top wide and the bottom narrow.
Flatten the bottom half with a rolling pin, then flatten the wider top into a triangle. I like to roll the top of the dough slightly wider than usual to give more space for the filling.
Place a block of cheese, a piece of butter, and a small spoonful of birria beef at the wide end.
Roll down toward the point, gently tugging for tension, and place seam-side down on a baking tray.