Purée the beans, lime juice, chilies, garlic, scallions, minced cilantro, cumin, olive oil, hot sauce, salt, pepper, and cayenne in the processor, adding enough stock to obtain a soft purée. Correct the seasoning, adding salt, chilies, or lime juice to taste. The mixture should be highly seasoned.

Transfer the hummus to a bowl and garnish with cilantro sprigs. (If you want to get fancy, make decorative lines on top with a wet spatula.) Serve the hummus with the Paleface Chips below.