1. Wash the duck under cold running water and pat thoroughly dry. With poultry shears or a sharp knife, trim the quarters, cutting away all exposed fat.
2. In a shallow glass, porcelain or stainless-steel pan large enough to hold the duck quarters in one layer, mix the oil, vinegar, salt and a few grindings of pepper.
3. Add the onion, garlic and bay leaves. Lay the duck in this marinade, baste thoroughly and marinate at room temperature at least 3 hours, turning the pieces every half hour.
4. When you are ready to broil the duck, remove it from the marinade. Strain the marinade through a fine sieve and discard the vegetables. Preheat the broiler to its highest point.
5. Arrange the duck, skin side down, on the broiler rack, sprinkle lightly with salt and broil 4 inches from the heat for about 35 minutes, regulating the heat or lowering the rack so the duck browns slowly without burning.
6. Baste every 10 minutes or so with the marinade. Turn the pieces over with tongs, sprinkle with salt and broil 10 to 15 minutes longer, basting 2 or 3 times with the marinade.
7. When the duck is tender and a deep golden brown, arrange it on a heated serving platter. Moisten with a tablespoon or so of the pan drippings if you wish and serve at once.
