Thaw pastry according to package directions. Cut pastry, lengthwise, in three 3-inch wide strips. In the center of one strip of pastry, lay 5 sausages end-to-end. Fold pastry over sausages. Press edges of pastry with a fork to seal. Cut into 1-inch sections and place individual sausage rolls, seam side down, in a lightly greased shallow baking pan. Repeat with remaining sausages and puff pastry.
In a small bowl, combine egg and water. Lightly brush the top of each roll with egg mixture. Bake in a 375 degree F oven about 25 minutes or until golden brown. Place rolls on paper towels to drain. Serve warm with your favorite mustard, if you like. Makes 30 bite-size rolls.
Wrap and chill rolls up to 3 days or freeze up to 2 weeks. To reheat bake in a 350 degree F oven for 5 minutes.