Roll puff pastry out with flour, thinly. Cut into 3 to 4-inch lengths - the same size as the plantains.
Spray nonstick cooking spray onto a cookie sheet. Place rolled-out puff pastry onto sheet. Place marinated plantains in center of each puff slice. Roll up. Prepare egg wash (2 eggs beaten), using a pastry brush paint egg wash on all sides of pastry. Bake for 20 minutes at 400 degrees.
Sauce for Dominican Plantains: Drain and strain marinade, add thickening (1 tablespoon cornstarch to 1 cup water, mix well). Bring all liquid to a boil for 3 to 5 minutes. Drizzle on plate,place baked plantains (2 to a plate) and drizzle sauce on top.