Hot and Sour Soup

Ingredients

• 7 oz extra-firm tofu , drained
• 4 Tb soy sauce , divded 1 + 3
• 1 tsp toasted sesame oil
• 3 Tb cornstarch + 1 tsp + ½ tsp
• 1 pork loin chop , boneless, center-cut, ½" thick, about 6 oz, trimmed of fat, cut into 1" by ⅛" matchsticks
• 3 Tb cold water , + 1 additional tsp
• 1 large egg
• 6 C low-sodium chicken broth
• 1 C bamboo shoots , from 1 5 oz can, sliced lengthwise into ⅛"-thick strips
• 4 oz fresh shiitake mushrooms , stems removed, caps sliced ¼" thick, about 1 C
• 5 Tb black Chinese vinegar
• 2 tsp chili oil , see note above
• 1 tsp ground white pepper
• 3 medium scallions , sliced thin