In a large pot, combine the vegetable broth and water. Bring to a boil over medium-high heat.
nce the broth is boiling, add the sliced mushrooms, bamboo shoots, tofu cubes, and julienned carrots. Stir well and reduce the heat to medium. Let the soup simmer for about 5 minutes,
Stir in the soy sauce, rice vinegar, chili paste or sriracha, and ground white pepper. Taste the soup and adjust the seasoning as needed, adding salt or more soy sauce for saltiness, more vinegar for acidity, or additional chili paste for heat.
Give the cornstarch and water mixture a quick stir to recombine, then slowly pour it into the soup while continuously stirring. Continue to simmer the soup for another 2-3 minutes until it thickens slightly, achieving a silky consistency.
Remove the pot from heat. Stir in the sesame oil, which adds a rich, nutty aroma to the soup. Ladle the hot and sour soup into bowls and garnish with chopped green onions and fresh cilantro, if using.