Suan La Tang (Hot and Sour Soup)

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

Instructions

1. For the pork: Combine the soy sauce, brandy, and cornstarch in a medium bowl; add pork, and toss until combined. Let sit at room temperature for 15 minutes.
2. For the soup: Whisk together stock, soy sauce, vinegar, cornstarch, pepper, salt, cayenne, and ¹⁄₄ cup water in a 4-qt. saucepan, and bring to a boil over medium-high heat. Add pork, reduce heat to medium-low, and cook, stirring occasionally, until soup thickens, about 30 minutes. Add tofu, potatoes, and mushrooms, and cook until potatoes are tender, about 15 minutes.
3. Without stirring, slowly drizzle egg into simmering soup in a thin, steady stream. When egg strands float to surface, stir in oil. Ladle soup into serving bowls and garnish with cilantro.