Add the olive oil to your slow cooker, the chopped onions, and freshly minced garlic.
Top that layer with the chopped or sliced carrots and chopped celery as well.
Now place the peeled or unpeeled bite-size pieces of the sweet potatoes into the slow cooker.
Rinse the lentils, let them drain, and look for any debris, if there is any. Add these to the slow cooker now.
Rinse and drain the garbanzo beans and layer those on top of the lentils in the slow cooker.
Now sprinkle the spices into the slow cooker. This recipe has turmeric, coriander, cumin, cayenne pepper, cinnamon, and salt. Oh, I wish you could smell this soup right now! The cayenne pepper gives it a little kick, so it's optional.
Add the vegetable broth right now. I would start with 1-1/2 quarts of broth and then add the leftover vegetable broth as the soup cooks if needed.
Place the lid on your slow cooker and cook on high for 3-4 hours, or on low for 6-8 hours or until vegetables are tender. If your slow cooker is too small, use a soup pot. Bring the soup to a boil and simmer until the vegetables are tender.
When the soup is finished, lift the lid and stir in the chopped kale, squeeze a lemon on top of the kale and add more salt if needed. Enjoy!