Preheat oven to 375 degrees. Slice each pita pocket in half with kitchen scissors. Combine cheeses in mixing bowl. Pour in pizza sauce and add salt and pepper. Stir to blend all ingredients. Take a pita pocket in your hand and rest the uncut side of the pita on a square of foil. The opening should be facing the ceiling. Spoon a fourth of the cheese mixture inside. Repeat this for the remaining 3 pockets. If using veggies, place them equally on top of the cheese mixture in each of the pockets. Wrap pitas individually in foil sheets and seal shut. Then gently shake each one to spread around the filling inside. Place foil-wrapped pita-pizzas on a baking sheet and bake for 8 to 10 minutes or until cheese is melted. Carefully remove from baking pan and cool 2 to 3 minutes before unsealing.