Rub coconut oil on potatoes, poke a few times with a fork, and bake in oven (just put them on the rack, no foil) at 400 degrees until forks inserts easily. I usually do this the night before.
Cool potatoes completely
Peel potatoes and shred with a cheese grater (This takes only a few seconds)
Heat up a large skillet over medium/high heat with about 1/4 cup of coconut oil or butter
Either make patties or place hash into skillet loose
Wait for them to brown before turning!
Notes
Don't forget that you can freeze before cooking. You don't need to thaw, it will just take a few more minutes to cook.