Place a large pot or dutch oven over medium-high heat. Brown the chorizo. Add the onions, garlic, celery, and kale to the pot and sauté with the chorizo until the vegetables start to become tender, about 5 minutes, stirring often. Add the lentils, tomatoes, and chicken broth and bring it all to a simmer. Turn the heat down to low, cover the soup, and simmer for about 20 minutes or until the lentils are soft, stirring often so that the soup doesn't stick as it thickens. When the lentils are soft and the soup has thickened, taste for seasoning. Add salt as needed and serve. Serve with crusty bread.