Choose a saute pan large enough to hold all of the scallops in one layer without overcrowding the pan or without them touching each other. Cook in batches if necessary. Heat the oil and 1 tablespoon of the butter until nearly smoking. Add the scallops and do not move or shake pan, but allow the scallops to brown well on one side before tossing the pan to flip them or gently turning them with a spatula to cook the second side.
Remove the scallops from the pan and place on a warm serving platter. Return the pan in which the scallops had been cooked to the fire, add the remaining 2 tablespoons of sweet butter, and cook until the butter begins to turn a light brown color. When the butter has browned to a hazelnut color add the lemon juice and chopped parsley.
Pour the classic lemon butter over the scallops, garnish with heart-shaped croutons and serve promptly.