Preheat oven to 375°. In heavy skillet, heat 2 Tbs. olive oil. Add chopped onions and garlic and cook until onions are caramelized. Set aside in a small dish. Add sausage to skillet, browning and chopping into small pieces (like chopped hamburger). Pour off oil and drippings and set aside.
Lightly brush pizza shell with olive oil, then spread Bove's Chianti Mushroom Sauce evenly over shell. Sprinkle grated mozzarella evenly over sauce, then add cooked sausage, onions and sliced mushrooms, also arranging evenly. Sprinkle pizza with fresh chopped basil and parmesan cheese. (Can arrange whole basil leaves instead of chopped, if preferred). Bake directly on oven rack for 15-20 minutes until brown and bubbly.
Serves 2-4