Puff pastry squares folded over arequipe or guava paste, brushed with egg and baked with sugar on top. Twenty minutes, and both fillings are sold ready made. Makes four.
Both fillings are sold ready made in any Colombian shop and there is no reason to make them: arequipe is dulce de leche and bocadillo is the solid guava block sold wrapped in dried leaves. Use less filling than feels right. Guava paste and arequipe both liquefy in the oven, and an overfilled pastry splits along the seam and empties itself onto the tray. Seal the edges firmly with egg and then with a fork, in that order, since egg is the glue and the fork is the reinforcement. Molten sugar burns badly, so the cooling minutes are not optional.