In a saucepan bring chickpeas and soaking water to a boil. Simmer over medium heat for about 1 1/2 hours. In a saute pan heat olive oil and add garlic and onions. Continue to saute until just golden. Add the cilantro and continue to saute a bit longer. Transfer onion mixture to chickpeas and season with salt and pepper. Add mustard and cayenne. Cover and return to the simmer for another hour, or until chickpeas are tender.