Melt the butter over medium heat in a large Dutch oven or soup pot.
Add the diced onion, chopped carrots, chopped celery, salt, and pepper. Sauté over medium heat until soft and fragrant, about 5 minutes.
Stir in the minced garlic and lemon juice.
Add the chicken stock/broth, increase the heat to high, and bring to a boil.
Once boiling, reduce to a simmer and stir in the canned beans and cooked turkey meat. Let the soup simmer for about 20 minutes.
Once the soup is done simmering, mix in the fresh kale leaves (discard the stems).
Remove the turkey and white bean soup from the heat, scoop it into bowls, and serve warm. Enjoy!