Step 1

Preheat the oven to 425 degrees F. Line a baking sheet with aluminum foil.

Step 2

Make a series of 1/8-inch slices along each potato, slicing 2/3 of the way through.

Step 3

Stir together the butter, oil, thyme, garlic, 1/4 teaspoon salt and 1/4 teaspoon pepper in a small bowl. Rub the potatoes all over with the mixture, getting in between the slices.

Step 4

Place on the baking sheet and roast until the center of the potatoes are tender and the outside is crisp, 50 minutes to 1 hour. Halfway through the roasting time, remove the potatoes from the oven and run a fork gently across the tops of the potatoes, using light pressure, to fan the slices and separate them from one another.

Step 5

Meanwhile, stir the yogurt and scallions with a pinch salt and a pinch pepper. Serve the sauce with the potatoes.

Step 6

Per serving: Calories: 150; Total Fat 4 grams; Saturated Fat: 2 grams; Protein: 4 grams; Total carbohydrates: 24 grams; Sugar: 8 grams; Fiber: 4 grams; Cholesterol: 10 milligrams; Sodium: 260 milligrams