A sit start power line for sure! Without giving too much away, try to control your swing while powering up to the flat ledge to mantle out.
When you approach The Pasture, a rather large boulder with Andy's Arete will present itself. Walk approacher's left around that rock beyond Cattleguard Arete. Once you are on the flat slab, Barn Door starts on the furthest left side.
The start is obvious and the lading area is excellent.
A single pad will do!