Strain the chickpeas; Transfer the chickpea water to a medium-sized saucepan; Add baking soda and garlic.
Transfer the chickpeas to a bowl. Add olive oil, mix well with your hands and add to the pot.
Bring to a boil, cook over medium-high heat for about five minutes, lower to medium-low heat and cook for another 15 minutes at a gentle boil. Remove from heat.
Strain the chickpeas into a bowl, keeping 2-3 tablespoons of the grains to garnish the dish. Store the cooking water in another bowl.
Put the tahini in a food processor, add lemon juice, and two to three tablespoons of the chickpeas' cooking water—process for a few seconds.
Add the chickpeas, along with the garlic, to the food processor and process for another two minutes until a perfectly smooth mixture is obtained. From time to time, stop the processor and scrape the chickpeas from the sides with a spatula.
Add 3-4 tablespoons of the cooked chickpea water and process for a few more seconds. Occasionally stop the food processor and scrape the sides with a spatula; if too thick - gradually add more of the chickpea cooking water.
Taste and adjust seasoning if necessary: Add salt and lemon juice gradually—process for a few more seconds.
Suppose you do not plan to eat Hummus that day. In that case, keep the remaining cooking water in the refrigerator, as the chickpeas thicken over time. Then, the next day adds the chickpea water gradually until you get the desired degree of thickness.