Soak the chickpeas

• Cover the chickpeas with water and add half of the baking soda.
• Boil for 3 minutes, turn off the heat and leave covered for one hour, or soak in cold water with the baking soda in the fridge for 8–12 hours.
• Drain and rinse thoroughly.

Cook the chickpeas until very soft

• Cover with fresh water, about 5 cm above the chickpeas, and add the remaining baking soda.
• Cook until completely soft, topping up the water and skimming off the foam and loose skins.
• A chickpea should mash into a cream with no firm centre.

Blend the chickpea purée

• Reserve the cooking liquid and strain it.
• Blend the warm chickpeas in batches with a few tablespoons of the cooking liquid until smooth.
• Freeze part of the cooled cooking liquid into small cubes, or use ice-cold water, and cool the purée quickly in a shallow container in the fridge.

Make the lemon garlic infusion and toast the cumin

• Blend the garlic briefly into the lemon juice, then leave for 10–15 minutes and strain through a fine sieve, pressing out the liquid well.
• Toast the cumin seeds in a dry pan just until fragrant, then grind them.

Combine the tahinis

• Stir each tahini thoroughly in its jar before measuring.
• Combine both tahinis with the strained lemon juice and a few tablespoons of cold water to make a smooth cream.

Blend the hummus

• Add the chickpea purée, ground cumin and some of the salt to the tahini cream.
• Blend for several minutes, gradually adding the frozen cooking liquid cubes or ice-cold water, counting all the liquid within the total amount.
• Adjust the consistency, adding the liquid gradually rather than all at once.

Season and serve

• Season with the remaining salt and lemon juice.
• The hummus should be soft and creamy, not stiff; it will thicken a little more in the fridge.