In a bowl, whisk together the soy milk, sesame paste, soy sauce, vinegar, sugar, chicken bouillon powder, and chili oil until smooth. Refrigerate while you prepare the remaining ingredients.

Heat the sesame oil in a frying pan over medium heat. Add the garlic, ginger, doubanjiang, and tianmianjiang, and cook for about 30 seconds until fragrant.

Add the chopped onion and cook until slightly softened.

Add the ground pork and stir until it is evenly coated with the seasonings.

Pour in the sake and cook for 2–3 minutes, allowing the alcohol to evaporate. Remove from the heat and let the nikumiso cool.

Cook the udon noodles according to the package directions. Drain and rinse thoroughly under cold running water, then drain well.

Pour the chilled sesame broth into a serving bowl. Add the chilled udon noodles, then top with the nikumiso, chopped green onion, and chili threads. Serve immediately.