Hot and Sour Soup (酸辣湯)

This is a traditional Szechuan dish.  It's so popular that it can be found in almost any Chinese restaurant.  It is spicy hot because we add white pepper at the end, not from use of hot pepper.

1. All ingredients, veggie and pork, are cut into matchstick-like slices.  (1) 1 piece of frozen bamboo shoots, (2) 3-4 dried mushrooms (香菇, immerse in cold water for 30-60 minutes, or hot water for 15-30 minutes, before cutting), (3) 3-4 dried black fungus (黑木耳, immerse in cold water for 30-60 minutes), (4) 1 small (or half a big) carrot (consider using a coarse-grained Mandoline slicer).  Note- Please follow the safety rules and be careful when cutting.
2. Slice 3-4 oz of lean pork and marinate in 2 tsp of rice cooking wine, 2 tsp of corn starch, and 2 tsp of soy sauce.
3. Slice a pack of soft tofu (嫰豆腐) into 1/2" x 1/2" x 1" chunks.  Beat 1 egg in a small bowl. Add 2 Tbsp of corn starch and 4 Tbsp of water in another small bowl (and stir into even mix).
4. (Prepare the Soup Base) Heat the soup base in a medium-sized pot (~8" in diameter) using a can of chicken broth (12-14 oz, ~1.5 cups), and 2 cans of water using the chicken broth can (~3 cups of water). Bring to boil and let simmer.
5. (High Heat) Heat 2 Tbsp of veggie oil in a flat bottom cooking pan and add all the veggie ingredients in Step 1 except the black fungus, stir-fry for 2-3 minutes.  Then add black fungus and stir-fry for 1-2 minutes.  Season with 1/4 tsp of salt and 1 Tbsp of soy sauce.  Pour all these cooked veggie ingredients into the soup pot.  Now, repeat the process (without seasoning), to stir-fry the marinated pork slices, for 1-2 minutes, till the pork turns white, but not fully cooked. Add pork slices into the soup pot. 
6. (High Heat for the Soup Pot)  Add the tofu chunks into the soup pot.  Season with 1/4 tsp salt.  
7. Bring the pot to boil.  Add the corn starch mix and stir the soup evenly until it is thickened. Add the beaten egg into the soup and stir evenly.  Note- The soup can be made thicker to your liking, by repeating the corn-starch-mix addition exercise (勾芡).
8. (Turn off Heat)  Add 1 tsp of white pepper and 1 Tbsp of vinegar, and stir evenly.  First, add soy sauce if the soup is in lighter than light brown color (1 tsp a time and stir evenly).  Second, taste first, then season to taste (by adding 1/4 tsp of salt, and/or 1/2 tsp of white pepper, and/or 1 tsp of vinegar). Garnish with chopped scallions and serve. Note- Consider allowing each individual to add white pepper and/or vinegar to his/her own soup bowl.  Here is a picture of the finished product.