How to Make It
Heat sesame oil and chile oil in a large saucepan over medium; add garlic, ginger, and scallions. Cook, stirring often, until scallion mixture is wilted and ginger is caramelized in spots, 5 to 7 minutes. Add star anise and cardamom; cook, stirring constantly, until fragrant, about 1 minute. Add chile bean sauce, and stir to coat. Add chicken broth, and bring to a boil over high.
Reduce heat to low, and simmer, stirring and scraping bottom of pan occasionally, until broth is spicy, aromatic, and has a slight smokiness from the cardamom, about 20 minutes. Strain broth; discard solids. Stir in soy sauce, adding more to taste.
Chile oil, black cardamom, and toban djan can be found at your local Asian grocery store.