Soak chickpeas in a bowl of water overnight, then drain. Place chickpeas in a pot with water to cover. Bring to a boil and simmer until softened, about 40 minutes. Drain in a colander and rinse under cold water. Puree with an immersion blender. Peel and chop garlic, then combine with salt and grind to a paste. Mix garlic paste with chickpeas. Stir in tahini, lemon juice, cumin and oil and season with salt. Cover and refrigerate 30 minutes.
Garnish with olive oil and cilantro to taste and serve with toasted bread.