Bring Stir-Fry Broth to a simmer in a large saucepan (do not boil). Remove mushrooms with a slotted spoon; set aside. Keep broth warm.
Heat 2 teaspoons sesame oil in a large nonstick skillet over medium-high heat. Add tofu; stir-fry 5 minutes or until lightly browned. Remove from pan. Heat 1 teaspoon sesame oil in pan. Add bok choy, ginger, and garlic; stir-fry 1 minute. Add 1/2 cup broth and mushrooms; cook 1 minute. Stir in noodles, soy sauce, and salt. Divide vegetable mixture evenly among 8 bowls; top with tofu and remaining broth. Sprinkle with cilantro. Drizzle with chili oil, if desired.