In a large pot over medium heat, warm the olive oil.
Add the onion, carrots, celery, sweet potato, and garlic, and saute until just softened (~ 8-10 minutes)
Add the lentils, broth, spices, and a few grinds of black pepper. Stir to combine
Bring to a slow boil before reducing the heat to low. Cover and simmer for 40-45 minutes, or until the vegetables and lentils are tender, but not mushy.
Working in batches, add about ½ of the soup in your blender or food processor. (An immersion blender would be great here too) Pulse a couple of times. You want the veggies to still be a bit chunky.
Turn off the heat. Stir in the turmeric, tomatoes, and greens, allowing them to wilt. Taste and adjust the seasoning, if needed.
Serve each bowl with a squeeze of lemon, parsley and generous sprinkle of Parmesan. Best served with a crusty garlicky baguette on the side.