Preheat oven to 400°.

Slice a small thin slice of potato skin off one side so the potato sits flat without rolling around. Carefully slice potatoes almost through ensuring that they stay in tact.

Drizzle a small amount of olive oil in the bottom of a baking dish and place the potatoes on the flat side with vertical sliced side up in the dish.

Place rosemary sprigs throughout the potatoes. Drizzle with olive oil.

Roast for 50-60 min or until you can stick a knife through the potato without any tension. If the potatoes are larger than golf balls, you will want to add approximately 10 min, but use the knife test to determine when they are ready.

While the potatoes roast, prepare the chive butter. Add a tablespoon of chopped fresh chives to softened butter until combined. Shape butter into a cylinder on plastic wrap and roll tightly. Place in fridge until potatoes are ready.

Remove potatoes from oven and place on a serving dish. Season with flaky sea salt (e.g., Maldon's) and pepper. Place a pat of the chive butter on each potato and let it melt. Serve with extra chive butter on the side.