1. Soak Chickpeas in water overnight. Drain and rinse then boil in fresh water for 10 minutes. Lower heat to a simmer and cook chickpeas for 1 hour or until tender. Cool in the cooking water. Drain and reserve liquid. (Chickpeas are cooked, when they are soft to bite, but still retain shape) Do not add salt to chickpeas while they are cooking, it make them tough.
2. Place chickpeas, garlic, cumin, tahini and salt in a food processor and mix until finely chopped. Gradually add lemon juice and olive oil and if necessary, enough of the reserved cooking liquid to make a soft puree. Hummus will keep in a sealed container in the fridge for up to a week.