For this slow cooker Cozy Lentil Soup recipe, I use green lentils as they hold their shape over low and slow heat. However, just about any type of lentil can be used!
Add the soup ingredients, seasonings, and broth to your slow cooker, and set it to cook on high.
After 4-5 hours, scoop out 4 cups of the soup and add them to the food processor. Blend with olive oil.
Add the smooth puree back into the slow cooker.
Adjust seasonings to taste, and add in the spinach leaves and chopped parsley. Replace the lid and continue cooking on low.
Finally, stir in the red wine vinegar and top with freshly grated parmesan. Enjoy!