Place cubed beef in a lightly-oiled slow cooker. In a small bowl, combine next 12 ingredients (coconut milk through pepper); pour mixture over roast.
Cover and cook on LOW for 6 to 8 hours or until beef is fork-tender and falling apart. Add mushrooms then raise slow cooker heat setting to HIGH.
Cover and cook for 20 to 30 minutes or just until mushrooms are tender. Serve immediately and enjoy!