1 pound linguiça or uncured Spanish chorizo, cut across into 1/8-inch-thick slices
1 large onion, peeled and chopped
1 clove garlic, peeled and minced
2 large baking potatoes, peeled and cut into 1/4-inch cubes
1 ½ heads kale, stemmed and coarsely chopped (about 6 cups)
4 cups chicken broth, homemade or low-sodium canned
1 tablespoon balsamic vinegar
2 teaspoons kosher salt
Freshly ground pepper to taste
3 plum tomatoes, cored and cut into 1/2-inch dice
Directions
Place the sausage in a large pot over medium-low heat and cook until it begins to render its fat, about 2 minutes. Add the onion and cook for 2 minutes. Add the garlic and potatoes and cook for 2 minutes. Add the kale and cook, stirring constantly, for 2 minutes longer.
Stir in the chicken broth, vinegar and salt. Bring to a boil, reduce heat, cover and simmer for 1 hour. Season with pepper. Stir in the tomatoes and cook, uncovered, for 15 minutes. Divide among 4 bowls and serve.