Preheat oven to as hot as you can get it. Line a large baking tray with paper.
Cut stems from caps and place into Thermomix bowl. Place caps onto baking tray.
Add garlic and Parmesan to Thermomix bowl and mill together for 10 seconds on speed 8.
Add basil, mozzarella and semi sundried tomatoes. Blend for 10 seconds on speed 7.
Divide mixture between mushrooms and bake for approximately 20 minutes. (You want the mushroom cooked but without being too soft. Time will depend on size of mushrooms used.)
Place mini Roma tomatoes and bocconcini onto pizzas and return to oven for 10 minutes until cheese has started to melt.
Place a few basil leaves on top to wilt slightly.
Serve hot.