Heat a large pot over medium heat and add the turkey sausage. Cook it while breaking it into small pieces until it is browned and no longer pink, about 6 minutes.
Add the onion, carrots, and celery to the pot. Cook for 5 minutes, stirring occasionally, until the vegetables begin to soften.
Stir in the garlic, cumin, smoked paprika, and cayenne pepper. Cook for 1 minute until the spices smell fragrant.
Add the rinsed lentils, diced tomatoes with their juice, chicken broth, salt, and black pepper. Bring the mixture to a boil.
Reduce the heat to low, cover the pot, and simmer for 30 minutes until the lentils are tender.
Stir in the chopped kale and cook for 3 more minutes until it wilts. Remove from heat.