Shred the potatoes on a box grater and rinse them in cold water until the water is mostly clear.
Wrap the shreds in a clean towel and twist firmly until they feel dry and loose.
Heat the oil and butter across a large griddle over medium-high heat and scatter the potatoes into 4 thin portions.
Season with the salt and pepper and cook without moving for 6 to 8 minutes until a deep brown crust forms underneath.
Flip each portion in sections and cook for 5 to 7 minutes until the second side is crisp and the centers are tender.
