Spaghetti Soup with Sausage

Cook spaghetti according to instruction on the package. Cut shiitake mushroom into small pieces. Cut bamboo shoot into thin strips. If you can’t find bamboo shoot, just omit it. Dissolve sweet potato starch in a little water. (If you don’t have sweet potato starch, skip this step. The soup will be more watery, that is all.) Bring water to boil, then put sausage, mushroom and bamboo shoots into the water. Let boil again, then reduce heat and simmer for 5 minutes. Add sugar, soy sauce and balsamic vinegar, continue to simmer for 2 minutes. Put the spaghetti and Napa cabbage into the soup. Add sweet potato starch water (if using). Mix well and cook for 3 more minutes. Season with ground white pepper and/or chili powder. (optional) Add chopped green onions and turn off heat.