Mix the hot broth with the peanut butter. Keep warm.

Heat a wok or heavy skillet over high heat. When it's hot, add the oil. When the oil is hot add the onion, mushrooms and garlic and the pickled vegetables, if using. Stir-fry until the onions soften, adding a bit of water as necessary to prevent scorching. Add the textured soy protein, soy sauce, brown bean paste and chili paste. When it bubbles, stir in the cornstarch mixture and stir until thickened. Remove from heat.

Run hot water over the noodles, drain, and divide them between 2 heated soup bowls. Heat the broth if necessary and pour over the noodles. Divide the sauce evenly between the two bowls, top with the chopped green onions and drizzle with the sesame oil. Serve immediately.