Chop the ends off the zucchini, the use a teaspoon and scoop out the inner part (white flesh), leaving an edge at each end to form boats. Scrape them out well but still leave a little zucchini in the bottom too
Place on a baking tray, then spoon one teaspoon of tomato paste into each boat, smoothing it over the bottom.
Add a sprinkle of cheese, then fill the zucchini with your toppings. Topping with cheese to finish.
Bake for 15-20 minutes or until cheese is melted and zucchini is cooked but still firm. You want to be able to pick them up and eat them like pizza sticks.