For the toppings: Heat a wok over high heat until smoking and pour in the peanut oil. Add the ginger, chiles and garlic and stir-fry for 30 seconds, and then add the ground beef and cook, breaking up the meat with a spatula, until browned, 2 to 3 minutes.
For the garnish: Mix together the chili oil, sesame oil, soy, peppercorns and chiles in a small bowl.
To serve, divide the noodles among 6 deep soup bowls and sprinkle the meat topping evenly over each. Pour the hot stock evenly over the noodles, and serve with the chili oil mixture, scallions and cilantro alongside at the table for garnishing.