Add the flour to a mixing bowl along with the salt and instant yeast. Add the warm (not hot) water and mix in with a spoon into a big ball of dough. Add more flour, flour your hands and knead the dough in your hands for around 5 minutes, adding flour as needed. You are aiming for the dough to become no longer tacky and no longer sticking to your hands. It should become pliable, tacky but not inclined to stick to your hands.
Return the ball of dough to the mixing bowl and cover it with a tea towel and leave it to rise for 1 hour. Sometimes the rise will be very big, sometimes not as much, but as long as it has risen a little bit from the start, you're good.
Measure out two pieces of parchment paper to roughly match the size of your pizza stone and set aside.
Place your pizza stone into the cold oven and put your oven on at 465°F (240°C) and begin to heat together for at least an hour while the dough is rising.
After an hour when the dough has risen, divide it into two balls. Don't compress the dough, just simply break it into two.
Dust some flour onto one of the sheets of parchment paper that you cut out and roll the dough out with a rolling pin to the edges of the parchment paper.
Mix your tomato sauce ingredients and spread half the sauce over the top of the rolled out pizza and spread it evenly using the back of a spoon.
Add sliced mushrooms.
Carefully slide the pizza with the parchment paper underneath it onto a wooden board.
Open the oven and carefully slide the pizza with the parchment paper from the wooden board onto the blazing hot pizza stone as quickly as you can and close the oven. Bake for 8 minutes.
After 8 minutes open the oven and using a spatula gently lift the pizza up, it should be lightly browned underneath. If it’s lightly browned underneath and the toppings are cooked, then it’s done.
Get the wooden board and carefully pull on the parchment paper to transfer the pizza and parchment paper back onto the wooden board.
Allow the oven and pizza stone a little time to heat up again to full heat between pizzas before repeating the process with the second pizza.
When the pizza has cooled slightly add the sliced avocado and drizzle on the cashew cheese before cutting into slices.