Combine broth, 1 cup (250 mL) water, fish sauce, ginger, star anise and cinnamon stick in saucepan; bring to a boil. Reduce heat to medium-low. Cover and simmer 10 min. until fragrant. Remove and discard ginger, star anise and cinnamon stick.
Meanwhile cook rice noodles according to package directions. Drain and divide among 4 bowls. Top with chicken, spinach and bean sprouts. Pour hot broth mixture over top. Sprinkle with cilantro and chili, if using, to serve.
Substitute cilantro with mint or Thai basil.
Substitute with vermicelli rice noodles, if preferred.
Wear latex gloves to protect your skin when slicing Thai red chili.