Remove from heat. Toss the scallops in the remaining 2 tablespoons olive oil and season lightly with salt and pepper. Wrap each scallop with a thin slice of prosciutto and secure each one with a toothpick. Don't overcrowd the pan or scallops won't brown properly.
Scallops are best when served a little underdone.
They should be soft to the touch but warm in the centers. Test one or two to determine cooking time before browning the whole batch. Remove from heat when done and keep warm. Divide the arugula among four dinner plates, placing it in a high mound in the centers of the plates. Divide the warm vegetables around the mounds of greens.