In a large nonstick frying pan, heat 1 tablespoon of the oil over moderately high heat until very hot. Season the scallops with the salt and pepper. Add half the scallops to the pan and cook until browned, about 1 minute. Turn and cook until browned on the second side and just done, about 2 minutes longer. Remove from the pan. Add the remaining tablespoon oil to the pan and repeat with the remaining scallops. Wipe out the pan. In the same pan, melt the butter over moderate heat. Add the scallions and cook, stirring, for 1 minute. Add the vermouth and orange zest. Cook until the sauce thickens slightly, about 2 minutes. Add the scallops and warm until just heated through, about 1 minute. VARIATIONS Seared Scallops with Lemon and Vermouth Use 1 teaspoon of grated lemon zest in place of the orange zest. Seared Scallops with Orange and White Wine Use 1/2 cup of dry white wine in place of the vermouth.