In a small bowl, whisk together cornstarch and 1/4 cup water; set aside.
Heat canola oil in a large stockpot or Dutch oven over medium heat.
Stir in garlic and ginger until fragrant, about 1 minute.
Stir in mushrooms until wilted, about 3 minutes.
Stir in chicken stock, bamboo shoots, soy sauce, rice vinegar, fish sauce, chili garlic sauce and pepper.
Bring to a boil; reduce heat and simmer until flavors have blended, about 10 minutes. Stir in tofu.
Stir in cornstarch mixture, stirring frequently, until slightly thickened, about 3 minutes.
Reduce the heat to low. While stirring the soup, gradually add eggs in a slow steady stream. Cook until the eggs are set, stirring frequently to create ribbons, about 2 minutes.
Remove from heat; stir in green onion and sesame oil.
Serve immediately with crispy wonton strips.
For the crispy wonton strips
Heat vegetable oil in a large stockpot or Dutch oven over medium high heat.
Working in batches, add wonton strips to the Dutch oven and fry until evenly golden brown and crispy, about 1-2 minutes. Transfer to a paper towel-lined plate.
Notes
Homemade wonton strips goes a long way. Store-bought will save some time in the kitchen but the homemade version below requires only 2 ingredients and tastes so much more fresh, crisp and light-textured.
Use a heavy pot. A heavy bottom pot, such as a Dutch oven, is ideal here for even heat distribution for the hot oil.
Cook in batches. If too many wonton strips are added at once, the oil temperature will drop and the wontons will absorb too much oil, resulting in soggy wonton strips.
Make ahead. The crispy wonton strips can be made 1-2 days in advance, stored in an airtight container at room temperature once cooled completely.
Use good-quality stock. The better quality your stock, the better your soup. Many brands love to pack in the salt so always opt for unsalted or a lower-sodium variety. Homemade stock is even better.
Use reduced sodium soy sauce.Reduced sodium has less sodium and less salt without compromising flavor.
Add more vinegar. If you like your soup particularly sour, add additional vinegar, to taste.
Make it vegetarian. Use vegetable stock for the chicken stock, skipping the fish sauce as well.
Lower the heat. Reduce the heat to the lowest setting before adding in the beaten egg in a slow, thin stream. A rolling boil will scramble the egg instead.
Mix it up. Swap out the tofu for cooked beef, chicken or pork.