Sprinkle a work surface with flour. Unfold 1 of the thawed puff pastry sheets on top of the flour.
Sprinkle some flour on the pastry. Using a rolling pin, and beginning at the center of the pastry, roll out to the far side. Then roll from the center toward you. After every few rolls, give the pastry a quarter turn and sprinkle the top and bottom of the pastry with more of the flour so the pastry does not stick. Keep rolling and sprinkling until the pastry is a large rectangle. Cut the dough into 6 equal pieces.
Put slices of guava paste on each piece of puff pastry. Brush the beaten egg along 2 edges of each piece with a pastry brush. Fold one half of each piece over the filling, enclosing it fully. Press the edges together with your fingers to seal them. With a knife make small cuts along the edges to make the chicharrón legs.
Place the chicharrones on a prepared baking sheet, spacing them 2 inches apart. Repeat with the remaining puff pastry sheet and guava paste.
Using a pastry brush, brush the tops of the chicharrones with the beaten egg and sprinkle with sugar. Put the baking sheet in the oven and bake for about 20 minutes or until they are puffed and golden.
Remove the baking sheet from the oven and set on a cooling rack to cool for about 5 minutes.