For the Pork
1 tbsp. soy sauce
1 tbsp. brandy
1 tsp. cornstarch
4 oz. pork tenderloin, cut into 1⁄4" cubes
For the Soup
8 cups chicken stock
3 tbsp. soy sauce
3 tbsp. white wine vinegar
3 tbsp. cornstarch
1 tsp. ground white pepper
1 tsp. kosher salt
1⁄2 tsp. cayenne
12 oz. firm tofu, drained and cut into 1⁄4" cubes
1⁄4 cup cubed potato
6 shiitake or wood ear mushrooms, cut into 1⁄4" pieces
1 egg, lightly beaten
1 tsp. toasted sesame oil
2 tbsp. finely chopped cilantro, to garnish