Combine all the ingredients from the cashews to the water in a blender or food processor and blitz into a paste.
Bake the pizza crust according to the package (or your recipe) directions half-way through until the crust is just beginning to turn brown. Take it out of the oven and spread the cashew cheese on top. You may not have to use all the cashew cheese now, reserve any leftovers to dollop on top of the baked crust. Continue baking the crust until is golden brown.
Meanwhile, make the balsamic reduction by heating the vinegar in a small pot over medium-low heat. Reduce until the vinegar can coat the back of a spoon and is reduced by about half.
Heat a small pan over medium heat and add a couple tablespoons of water and the asparagus. Cover and cook until tender, then remove the asparagus from the pan and reserve.
When the crust is baked, dollop over any remaining cashew cheese, sprinkle with red onion and top with the greens, diced avocado and asparagus. Drizzle over the balsamic reduction and serve.