In large saucepan, brown meat in oil on all sides; drain. Add the water, broth, sherry, soy sauce, onions, brown sugar, garlic, ginger, sesame oil and cayenne. Bring to a boil. Reduce heat; cover and simmer for 1 hour.
Stir in the mushrooms, carrots and bok choy; cover and simmer 20-30 minutes longer or until vegetables are tender. Meanwhile, cook rice according to package directions.
Divide rice among six soup bowls, 3/4 cup in each; top each with 1 cup of soup.