Soak the chickpeas overnight in plenty of cold water and the soda. The next day, drain and place in a saucepan with enough fresh cold water to cover them, and simmer for around 1 hour until they have softened.
Drain and keep ½ cup of the liquid. Place the chickpeas in the blender, together with the garlic, salt, pepper and lemon juice, and blend until the mixture is smooth.
Dilute the tahini in 1/4 cup of warm liquid (from the chickpeas) and add to the mixture, blending all the time. If the mixture seems too dry, add a tablespoon of liquid at a time until it reaches a nice consistency. Serve hummus drizzled with a little olive oil
2 cups chickpeas
½ tsp baking soda
2 cloves garlic, crushed
3/4 cup lemon juice
½ cup tahini
A little olive oil, salt, pepper