View photos of the edible and medicinal plant Acacia greggii [Senegalia greggii] (Catclaw acacia), profiled in Medicinal Plants of the American Southwest and Sonoran Desert Food Plants.

A passage from Sonoran Desert Food Plants:

Shuck the seeds from the pod. Soak the seeds overnight (or 24 hours will be better), strain, add fresh water, and repeat until the water is clear (this soak/strain process can be repeated ad nauseam in order to remove any potential digestive irritants).