Preset oven for broiling and preheat for at least 20-30 minutes depending on the size of the oven. Place a rack close to the element.
Line a sheet pan with foil. Center the baking shells on the sheet pan.
Place a little cube of butter on each shell.
Carefully grip and shape scallops and place them over the piece of butter.
Position a little slice of tomato, wrapping the scallop from the side of the hinge.
Season lightly with salt and pepper. Zest parmesan over, place another cube of butter over and zest parmesan again.
Place sheet pan under the broiler and broil for approximate 3-5 minutes depending on the size of the scallops.
Observe your scallops to see when they are ready. Scallops are ready when their flesh turn to a milky-white color, and they feel somewhat firm. Remove from oven, wait just a minute and enjoy!