Bring a large saucepan of water to the boil. Add the chopped potato and pumpkin pieces and cook till just tender; rinse through with cold water to ensure the steam doesn't keep cooking them. You don't want them over-cooked. Set aside.
Pre-heat oven to 200 degrees C.
In the meantime ensure all of the pizza toppings are prepared - sliced, chopped etc.
Gently toast pitas for a few minutes or until nicely toasted
Spread the tomato paste evenly over pita breads, then layer in specific order: sliced spanish onion, shaved ham, spinach leaves, potato and pumpkin pieces, semi dried tomatoes and then lastly top with the grated cheese.
Place pizzas on top shelf of oven and cook for aprox. 10-15 minutes or until desired taste is achieved.