How to Make It
In a medium pot, melt the butter over medium high heat until hot, then stir in the shallot, 1 teaspoon salt and 1/2 teaspoon pepper and cook, stirring occasionally, until the shallot is golden, about 6 minutes.
Stir in the potatoes and stock and bring to a boil. Reduce heat to a simmer and cook, uncovered, until the potato is tender, about 20 minutes. Tear the kale from the stems adding the leaves to the pot. Simmer the soup until the kale is tender, about 10 minutes more. Season to taste with salt and pepper and serve.