Add diced tomatoes and Medjool dates to a blender. Blend until smooth. Set aside.
Chop the celery, onions, white mushrooms, and bell pepper. Mince the garlic. Add all chopped veggies to the instant pot or a large saucepan. Sautee veggies for 7 minutes. Add a splash of water if sticking occurs. Add all remaining spices to sauteed veggies. Give a quick stir thru and cook an additional minute.
Add the rinsed and drained lentils and red kidney beans to the pan with sauteed veggies. Give a quick stir thru.
Add the veggie stock and blended tomato sauce to the pan with veggies. Give another quick stir thru and cover. INSTANT POT: cook on "High Mode" (Bean/Chili Mode) for 10 minutes. STOVE TOP: Bring to a boil over high heat then reduce heat to medium-low and simmer for 45 minutes, stirring frequently until the lentils are soft.
Rinse the kale leaves. Cut away the stems. Chop the destemmed kale leaves into small pieces.
Remove lid, add the chopped Kale to the pot. Stir thoroughly. Re-cover the pot and simmer an additional 10 minutes or longer until Kale has withered. NOTE: The longer the chili simmers the thicker the consistency of the chili.
Serve over cooked brown rice or a baked potato. Enjoy!