In 2 qt. saucepan; add chicken broth, fresh rosemary and smashed garlic. Bring to a simmer covered, remove from heat and let sit for 10 minutes. Remove rosemary and garlic. Bring broth to a boil and whisk in butter and polenta. Turn heat to low and cover pan with lid. Cook for 15 minutes, stirring often to prevent lumps. Uncover and stir in parmesan cheese. Immediately spread cooked polenta on a 15 inch round pizza stone that has been sprayed with cooking spray to form a 13 inch diameter pizza crust. Top with sauce, then mushrooms, chicken, mozzarella, then TOMA cheese.