For the noodles: Bring a large pot of water to boil over high heat. Add the noodles and salt, stir, and cook until al dente, about 4 minutes. Drain in a colander and rinse with cold water, and then shake out any excess water and transfer to a bowl. Pour the sesame oil over the noodles and toss well to coat.
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.
Stir in the cornichons, sesame paste, soy sauce, rice wine, vinegar and peppercorns and cook until the beef begins to crisp. Season with white pepper and remove from the heat.
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.
Sesame paste can be substituted with an equal amount of tahini mixed with 1 teaspoon toasted sesame oil.