Preheat oven to 210°C or 410°F, fan forced.
Add cheddar and parmesan cheese to mixer bowl, grate 15 sec/speed 8/MC on.
Cover base of rolled out pizza dough with pizza sauce, then lay down thinly sliced mozzarella.
Sprinkle with a little of the grated cheese mixture, just enough to lightly cover the base.
Follow with mexican shredded chicken and red onion.
Sprinkle over salt and mexican spice mix and then remainder of cheese.
Finish with lashings of chipotle mayo over the top of the pizza.
Bake 10-15 min in the oven.