Preheat oven to 425°. Toss cauliflower florets on a baking sheet with olive oil, salt and pepper and roast for about 30 minutes or until golden brown
Meanwhile, heat olive oil in a large soup pot over medium heat, add onion, carrot, celery and potato, season with salt and pepper, and saute until softened, about 15 minutes
Add lentils, chicken or turkey and seasoning, and stir to combine
Add stock and water and let simmer on medium low for about an hour
Add cauliflower (at anytime after it's roasted) and parsley
Serve soup with grated cheese and crusty bread