Fresh Mackerel, with White Piquante Sauce

Suppress the heads and the thin tail parts of four fresh, well cleansed mackerel; remove the skins and pare the meat into half hearts, lay these on a dish, season with salt, pepper, thyme, bay leaf, cut up onions, oil and lemon juice, turning them over at intervals. One hour later take the pieces from their pickle, dip them in flour and cook in clarified butter; when done and of a fine color, drain and dress them either in a straight row or in a circle on a dish and pour around a white sharp (piquante) sauce (No. 538).