One of the truly great taste combinations is mushrooms and cheese, so it is a no-brainer to put them together on a pizza. What is not a no-brainer is making mushroom pesto to put on the pizza instead of tomato sauce. That is brilliant. Another brilliant thing is to roast the mushrooms in the oven before making them into pesto. How have I never roasted mushrooms before? The smells coming out of the oven while they were roasting were just incredible….