The original recipe calls for russets, but you can use something like red potatoes or Yukon Gold if you prefer. You are also better off using small potatoes rather than big ones.
I served them here with meatballs.
3 oz (6 Tbsp.) lactose-free butter (I think I used 3 or 4 Tbsp.)
8 small-medium baking potatoes (about 4 lbs.), scrubbed (I used 6)
16 fresh flat-leaf parsley leaves (I used 12)
Preheat oven to 450 °F. Place a roasting pan in oven with butter (I used a foil-lined rimmed baking sheet); once butter has melted, barely a minute or two later, remove pan from oven.
Halve each potato lengthwise. Place one parsley leaf in the center of each cut half, then sprinkle cut sides generously with salt. Arrange face-down in pan with melted butter; try not to nudge them around or the leaves will move off-center. Roast potatoes for 35 to 45 minutes (depending on size) until tender. There’s no need to turn the potatoes over unless they get so dark underneath (this can happen with a thinner roasting pan or oven than runs hotter) that they risk overcooking before becoming fully tender; if so, just flip the potatoes for the remaining roasting time.
Serve immediately, cut sides up.