"Tantanmen (dan dan noodles) is a Chinese noodle dish, and very popular in Japan. This contains some Chinese spices that are not very common but many Chinese supermarkets have them in the spices aisle."
Heat sesame oil in a skillet over medium heat; add doubanjiang. Cook and stir shallots, garlic, and ginger until fragrant, about 30 seconds. Add ground pork; cook and stir until browned, about 3 minutes.
Mix soy sauce, tahini, sake, miso paste, and tianmianjiang into pork mixture until evenly combined. Add chicken stock; bring to a boil. Mix rice vinegar and rayu into pork mixture; add spinach. Simmer soup over low heat for 10 minutes.
Put noodles in a bowl of hot water to separate; drain. Mix noodles into soup and garnish with green onions and Thai chile peppers.