By David Cohlmeyer

Makes 4 large servings

The type of potato you use in this recipe makes a big difference in the texture of the soup. Starchy baking potatoes provide a wonderful, mealy texture in contrast with the kale. Waxy boiling potatoes provide a fascinating, firm contrast to the kale. To be sure the kale becomes tender, cut out any larger stems prior to cooking.

5 cups chicken or vegetable broth
2 cups diced potatoes
4 Tbsp (1/4 cup) unsalted butter
1 cup very thinly sliced onions
4 cups chopped kale leaves
1/4 cup red wine vinegar or sauerkraut
sea salt or kosher salt, to taste
freshly ground black pepper, to taste
1/4 cup sour cream

In a large pot, add the broth and bring it up to a simmer. Stir int he potatoes. Bring the broth back up to a simmer.

Meanwhile, in a large skillet, heat the butter over medium heat. When it has melted, sauté the onions until lightly browned, about 10 to 12 minutes. Stir the onions and kale into the simmering broth. Return the broth to a simmer. When the potatoes and kale are tender, stir in the vinegar. Taste and add salt and pepper as needed. Serve each portion with a dollop of sour cream.