Sausage, Potato & Kale Soup

Cook sausage in a large heavy pot over medium heat, stirring often to crumble, until browned, about 5 minutes. Add onion, celery and garlic; cook, stirring often, until softened, about 6 minutes. Add tomato paste; cook, stirring constantly, for 1 minute. Stir in tomatoes, potatoes, broth, pepper and salt. Bring to a simmer over medium-high heat. Cover; reduce heat to medium and simmer until the potatoes are tender, about 20 minutes.

Stir kale into the soup. Continue simmering over medium heat, stirring occasionally, until the kale is wilted and tender, about 5 minutes. Stir in lemon juice.

Divide the soup evenly among 6 bowls; garnish with celery leaves and Parmesan, if desired. Serve immediately.