1Melt butter in a pot over medium-high heat. Saute onion in hot butter until tender, 5 to 10 minutes. Stir chicken broth and tomato into onion.
2Heat broth mixture to near-boiling and stir kale into liquid until completely submerged. Cook until kale wilts, 3 to 5 minutes. Stir beans into soup and cook until heated through, another 2 to 3 minutes.
Footnotes
Cook's Note:
Substitute your favorite canned beans for the white beans and season the soup with your favorite spices.