Remove any fat from the roast and cut into bite size pieces. In a large pot, heat oil and brown meat, about 5 minutes. Add 1/2 cup of water, onions, celery, bean sprouts, and 1/4 cup soy sauce. Reduce heat, cover and simmer for 1 hour.
Dissolve cornstarch in 1/2 cup water and add to beef. Add Chinese bead molasses, 2 Tablespoons soy sauce and mushrooms. Simmer for 15 minutes.