PREHEAT oven to 375˚F (190˚C).
COOK vegetables according to package directions. Set aside to cool slightly. Coarsely chop and combine with chicken, cheese, salt and pepper. Set aside.
DIVIDE puff pastry into 2 halves. On a lightly floured surface roll each half into a 10 X 14 inch (25 X 35 cm) rectangle. Cut rectangles in half lengthwise to make four 5 x 14 inch (12 x 35 cm) strips. Place 1/4 of filling along one long edge of a pastry strip. Fold pastry over filling and roll into a tube shape. Seal edge with beaten egg. Place seam side down on a parchment lined baking sheet and brush with egg. Repeat with remaining pastry strips and filling.
BAKE in preheated oven for 15-20 minutes or until golden brown.
Refrigerate any leftovers and pack in lunches the following day. Experiment with kid friendly fillings – chopped ham, pepperoni, Cheddar or Mozzarella cheese plus cooked or frozen vegetables they like.
Serve with a side salad.