A Thai-Chinese Street Food Stir-Fry: Gai Pad King

For the Prik Nam Pla (if using): In a small bowl, combine fish sauce, lime juice, Thai chiles, shallot, and garlic (if using). Set aside. For the Stir-Fry Sauce: In a small bowl, stir together Golden Mountain seasoning sauce, oyster sauce, black soy sauce, fermented yellow bean paste, fish sauce, and sugar until well-combined. Set aside. For the Stir-Fry: Add 1 1/2 teaspoons of sliced ginger (1/5 of total amount; 5g), cilantro roots (or stems), and white peppercorns to a granite mortar and pestle and pound into a fine paste, 3 to 5 minutes. Add garlic, and continue to pound until rough paste forms, about 1 minute. In a wok or large skillet, heat oil over high heat until shimmering. Add the ginger-garlic paste and cook, stirring constantly, until fragrant, about 30 seconds. Add the chicken and remaining sliced ginger (30g), and cook, stirring frequently, until chicken is just cooked through, about 1 minute and 30 seconds. Add stir-fry sauce and wood ear mushrooms and continue to cook, stirring frequently, until sauce is reduced to a glaze that evenly coats ingredients, about 1 minute. Add long chiles and 1 teaspoon (5ml) water around sides of wok and use a wok spatula or wooden spoon to scrape up any browned bits stuck to wok. For Serving: Remove from heat and stir in scallions to lightly wilt them. Serve immediately with cooked jasmine rice, passing prik nam pla at the table.