I often use the Schär gluten free pizza bases quite often to make pizza.
The process I use is to take the Schär base. This is then topped with tomato. I personally prefer to use passata or other tomato base on my pizza, but my daughter prefers that I use tomato puree. On top of this I use a mix of grated cheese, usually mozzarella and cheddar.
Toppings vary and depend on what we have in the fridge. On this occasion I used salami, pepper, onion, and mushrooms. I usually pre-cook the mushrooms with some garlic butter.
The pizza is then cooked in a hot oven for about ten minutes, until the cheese is cooked and browned.