Cut the mini potatoes in half.

Melt oil and butter in a large non-stick skillet. Place potatoes cut side down in a single layer (try to fit as many as possible; the rest can just sit on top of them).

Cover the pan and let cook on medium-low heat until the potatoes are soft and the outsides are crunchy – about half an hour. Check occasionally to see if the bottom slices are getting too dark. If they are, add a little oil (about one tablespoon) and mix the potatoes so they all get crispy and brown. Sprinkle with salt and pepper.

To serve, top with shredded shallots and chopped fresh dill. Serve in a large serving dish with a generous dollop of sour cream and sprinkle with additional freshly ground black pepper.