"This is perfect for cold weather, one of the best ways to cook with kale. It's a soup dish with the most wonderful crunchy texture from kale. The addition of basil pesto takes this traditional lentil-base soup to the next level. Serve hot with shaved Parmesan cheese."
Heat 2 tablespoons olive oil in a heavy pot over medium heat; cook and stir onion, carrot, and garlic in hot oil until the onion is translucent, about 3 minutes.
Break sausage meat into small pieces and stir into vegetable mixture; cook and stir until meat is slightly golden, about 5 minutes. Stir butter beans, water, and tomato into sausage mixture; bring to a simmer and cook until tomatoes soften, about 5 minutes.
Stir kale and pesto into the sausage mixture; cook and stir until kale wilts slightly, 3 to 5 minutes. Remove pot from heat and stir basil leaves into soup.