In a non-stick skillet large enough to hold the scallops in one layer heat 1 tablespoon of the oil over high heat until it is hot but not smoking and in it sear the scallops for 1 to 2 minutes on each side, or until they are golden brown and just cooked through.
Transfer the scallops with a slotted spoon to a small platter and keep them warm, covered loosely.
Add the remaining 1 1/2 tablespoons oil to the skillet and in it cook the garlic over moderate heat, stirring, until it is pale golden.
Add the tomato and the thyme and cook the mixture, stirring, for 1 minute.
Season the tomato mixture with salt and pepper, spoon it over and around the scallops, and sprinkle the scallops provencale with the basil.