Heat oven to 350 degrees F.
- Scrub potatoes, dry and prick skin with knife in several places. Place potatoes directly on the oven rack. Bake until soft and cooked through about 40 minutes.
- Allow potatoes to cool slightly and peel the skins with a paring knife. Place potatoes in a shallow bowl, and break into smaller 1 inch pieces using the side of a spoon. Take care not to mash the potatoes, though a few can be broken into smaller pieces. Set aside.
- Meanwhile, in an oven safe pan, heat olive oil and butter. Once the butter ceases to foam, add potatoes, nutmeg, salt and pepper. Toss gently but thoroughly so flavors combine, but the potatoes do not completely break down.
- Press potato mixture into the skillet to create a “cake” and let cook on medium high heat until the edges begin to brown, about 15 minutes. Place pan under broiler until top of cake browns lightly, about 5 minutes.
- Meanwhile, in a small bowl, mix yogurt, chives, salt and pepper. Remove pan from oven, cover with platter, serving side down, and flip to release potato “cake” onto platter. Smooth the yogurt on top of the potatoes, slice into wedges and serve immediately.