Soak the chickpeas in plenty of water overnight or for at least 8 hours.

The next day, drain the chickpeas. Add them to a saucepan along with the baking soda and enough water to generously cover them. Bring to a boil, then simmer, skimming off any froth, for around 45 minutes or until completely tender. You should be able to turn them into a paste between your fingers without any resistance.

Drain the chickpeas, then tip them into the jug of a food processor along with the tahini, lemon juice, garlic, ice cubes and 2/3 tsp salt. Blend until smooth. If all of the ice is incorporated and the hummus feels too thick, add a little cold water (I don’t use the soaking water to have less of the baking soda in the final hummus). The hummus firms up in the fridge, so after blending it should feel just a little bit too creamy.

For the topping, simply heat the harissa and olive oil in a small pan until it sizzles and the oil has turned into a ruby red. Turn off the heat. Roughly chop the coriander, then pour the harissa oil over the hummus followed by the coriander.