Peel the potatoes and cut a thin slice from one long side of each so they will sit flat. Place the potatoes on a cutting board. With a sharp thin knife, cut 1/8-inch wide slits crosswise to within 1/4 inch of the bottom.
Place the potatoes in a spoke fashion in cast iron skillet or 10-inch pie plate.
Drizzle with about half of the butter, fanning the potatoes so the butter gets into the slits. Sprinkle with the salt. Bake for 30 minutes.
Baste with the additional butter and sprinkle with the bread crumbs. Bake the potatoes for 20 minutes longer or until tender.
Sprinkle with the cheese and bake for 5 minutes longer.
Top each cooked potato with chives and a dollop of sour cream.