Add all remaining ingredients except the spinach, mixing well to distribute and break up any clumps of tahini. Bring to boil, then cover and cook on low for 30 minutes.
Toss in the spinach. Cook for another 10 minutes, until lentils are soft.
Serve hot. Let cool before store in a container in the fridge for 1 week.
Notes
*You may need to add some water when reheating the soup.
Recipe by Lenses and Lentils at https://lensesandlentils.com/green-tahini-lentil-soup/