In a medium skillet over medium heat, roast the garlic, turning frequently, until light brown, about 15 minutes. Remove from the heat, cool, and then slip off the skins. Set aside.
Bring about 8 cups of water to a boil in a saucepan and drop in the beans. Bring back to a boil and cook for 5 minutes. Reserve 3/4 cup of the cooking water before draining. Drain the beans and cool.
Transfer the garlic into a food processor and chop coarsely. Add the beans, cayenne pepper, cumin, salt, pepper and process in the food processor. Add the olive oil, lime juice and cilantro and pulse to combine. Add the reserved water a little at a time while processing until smooth (you may not need to add all of the water). Use pita chips for dipping.
Recipe adapted from Home Cooking with Trisha Yearwood (c) Clarkson Potter 2010