Preheat the oven to 220 degrees C.
In a bowl mix the Teriyaki sauce ingredients together; Tamari, Mirin, Sake and Caster sugar, set aside. In a fry pan heat the oil on a medium heat. Add the chicken and cook till its tender, with some paper towl mop up any excess oil in the pan being careful not to burn yourself. Pour in the Teriyaki sauce over the chicken and cook till the sauce thickens. Transfer chicken to a seperate bowl to cool.
Sprinkle the cheese on the pizza base. Sprinkle on the mushrooms, onion and chicken. Garnish with Spring onion. Bake for 20 minutes or until the cheese has melted and the base becomes crispy. Enjoy!
You can use any other meats, tofu or vegetables. See whats in season!