Check to see if the scallops are alive by holding them under cold running water. They should close firmly within a few seconds. A dead scallop will very soon give off a bad smell; discard it.
You can ask your fishmonger to clean the scallops for you, but as you want them to be as fresh as possible, the best thing is to clean them yourself. With a sharp knife, cut the scallops open: Pressing the knife firmly against the flat half of each shell, cut the adductor muscle. Once you have done this, the shell will open by itself. Remove the muscle (the scallop) and the orange roe; discard the rest. Gently wash the scallops and the roe under cold running water.
Mix the honey and vinegar in a small warmed bowl (the two will not combine easily if cold).
With a thin sharp knife, cut the scallops horizontally into thin slices. There is no fixed rule as to how thin the slices should be — I try to make them as thin as possible, but the last two slices always end up thicker than the others.
Spread the slices out on a plate. Place the roe on two plates and make 8 small slits in each one with a sharp knife. Sprinkle each roe with 2 to 3 drops of the honey-vinegar mixture. Drizzle a few flakes of salt over the scallops and serve immediately, with lime, if desired, on the side.