1. Combine mushrooms and 2 cups boiling water in a bowl. Cover and let stand 30 minutes or until tender. Drain and rinse in a colander; drain. Chop mushrooms.
2. Bring broth to a simmer (do not boil). Keep warm over low heat.
3. Heat butter and oil in a large saucepan over medium heat. Add onion and garlic to pan; cook 8 minutes or until tender, stirring frequently. Add rice; cook 1 minute, stirring constantly. Add wine; cook 2 minutes or until absorbed, stirring constantly. Stir in mushrooms, thyme, and bay leaf. Add broth, 1/2 cup at a time, stirring constantly until each portion of the broth is absorbed before adding the next (about 25 minutes total). Discard bay leaf. Stir in cheese, salt, and pepper.