Heat the olive oil in a large pot over medium heat. Add the onions, garlic, carrots and celery. Sauté, stirring frequently for about 5-6 minutes.
Add the red lentils, broth, cumin, coriander and turmeric and stir to combine. Bring to a boil, then lower heat to a simmer for 30 minutes, until the lentils are soft.
Place the cashews and lemon juice in a high powered blender, along with 2 cups of the soup. Blend on high until creamy and smooth.
Add the creamy blended mixture back to the pot and stir in the spinach/kale. Cook for a few minutes until kale has softened, if using.
If you want a thinner soup, add ½-1 cup of water or more broth.
Taste and add salt/pepper and cayenne pepper. Serve immediately with fresh chopped parsley on top and enjoy!
