The broth for beef pho is generally made by simmering beef bones, oxtails, flank steak, charred onion, charred ginger and spices. For a more intense flavor, the bones may still have beef on them. Chicken bones also work and produce a similar broth. Seasonings can include Saigon cinnamon or other kinds of cinnamon as alternatives (may use usually in stick form, sometimes in powder form in pho restaurant franchises overseas), star anise, roasted ginger, roasted onion, black cardamom, coriander seed, fennel seed, and clove. The broth takes several hours to make