Remove stems from shiitake mushrooms. Slice caps into thin strips.
Cut bamboo shoots lengthwise into thin strips. Or not. It's up to you.
Wash and slice scallions. Get fancy and slice them on a diagonal.
Drain tofu. Cut into ½" squares.
assemble
Add chicken or vegetable broth to large (8 quart-ish) pot over medium heat. Add sliced mushrooms, bamboo shoots, rice vinegar, soy sauce, ground ginger, chili garlic sauce, sesame oil, and black pepper. Bring to simmer.
In a small bowl or measuring cup, prepare corn starch slurry by stirring together cold water and corn starch. Slowly drizzle into hot soup, stirring constantly.
Crack eggs into small bowl or measuring cup and whisk. (I like to use a measuring cup for the corn starch slurry, then use it again for the eggs. I like pouring these items from a vessel with a spout, and it's one less dish to wash.)Slowly drizzle beaten eggs into hot soup, letting the eggs form ribbons.
Stir in the tofu. Stir in the green onions, reserving some for garnish if desired.