The recipe (and this is a pretty big recipe) calls for a 1/2 teaspoon of real (Spanish) saffron. Saffron is expensive but imparts a particular flavor in addition to the color. A lot of Mexican grocery stores sell "Mexican Saffron" (Azafran Flors) which is much less expensive albeit weaker-tasting version. It's the entire crocus flower vs. just the pistils and you'l probably have to use a LOT more of it. Dried chickpeas need to be soaked for a very long time. 2-3 days is ideal.