Hot and Sour chicken and noodle soup

My SMIL made this as part of our New Year's Eve feast.  I was sicker than a dog, the kids refused to even try this soup or sushi or Peking duck but this saved me.  She sent us home with several more meals of this soup and it nursed me back to health.

2 tablespoons canola oil
1 small onion
Handful Shitake mushrooms, stems removed and sliced
Enoki mushrooms (dried, reconstituted chinese mushrooms can also be used)
1-inch piece fresh ginger, peeled and grated
1 tablespoon red chile paste, such as sambal oelek (I used garlic Chili paste)
1/2 cup canned bamboo shoots, rinsed well and sliced
shredded Napa cabbage
4 garlic cloves, minced
Baby Bok Choy (optional)
1 rotisserie chicken, skin off, chopped
1/4 cup soy sauce
1/4 cup seasoned rice vinegar
1 teaspoon salt
1 pinch red pepper flakes
2 quarts  Chicken Stock
1 inch piece of ginger, peeled but kept whole
1 pkg fresh Soba noodles
1 square firm tofu, drained and sliced in 1/4-inch strips
3 tablespoons cornstarch mixed with 1/4 cup water
Chopped green onions and cilantro leaves, for garnish

Heat the oil in a large pot over medium high heat
Add the ginger, garlic chile paste, onion, mushrooms and bamboo shoots and cook for 1 minute until fragrant.
Add the thinly sliced cabbage, garlic and bok choy and stir to combine.
Add soy sauce, rice vinegar, salt and pepper and stir again.
Add the chicken stock and ginger piece and bring to a boil. 
Simmer 10 minutes.
Add the tofu and noodles and cook for 3 minutes. 
Taste and adjust for seasoning. 
Make a slurry with the water and cornstarch and add to the soup, simmering until the soup thickens.
Top with chopped green onions and cilantro.