In a large skillet, heat oil over medium heat. Sauté mushrooms, anise, onion
and garlic until softened, but still crisp-tender, about 5 minutes. Drain.
Spread pizza crust evenly with pizza sauce.
Distribute vegetables over sauce.
Arrange shrimp on top of vegetables and top with Havarti.
Bake for 20 minutes, until golden and bubbly.
Cool for 5 minutes before cutting into serving pieces.