Coat a cast-iron skillet with olive oil. Place frozen rolls in the pan, leaving plenty of space for rising - if you can't fit all 12 rolls in your pan you can either make a second skillet or use a pie plate. Cover with a clean dishtowel and set in a warm place to rise until doubled in size, about 2 hours. Brush with melted butter and sprinkle with Porcini Sea Salt. Bake rolls at 400 for 12-17 minutes, until tops are golden-brown. Serve warm.