The key to this soup is to make sure your mushrooms, tofu, bamboo shoots, and seitan are sliced into long, skinny strips before you start cooking. This takes a little time but is 100% worth it.

Bring the water and the bullion paste to a boil in a medium to large pot.

Add the mushrooms, tofu, bamboo shoots, seitan, soy sauce, hoisin sauce and boil for an additional 5 minutes.

Stir in the vinegar and Chili Garlic Sauce, tasting as you add it, to make sure it's not too spicy for you. Lower heat and simmer for 3 more minutes.

In a separate, small bowl, mix cornstarch into cold water until totally dissolved.

Whisk this mixture into your soup until totally incorporated. Simmer for another minute or two until the soup starts to thicken. Remove from heat.

Garnish with slivered green onions and serve.