Swordfish steaks provide heart-healthy unsaturated fats, protein, vitamin A, potassium and other nutrients. They are relatively low in calories and saturated fat, though they contain significant amounts of cholesterol and sodium. Because they're so sturdy, swordfish steaks hold up well to all manner of marinades and all methods of cooking, including grilling, frying, baking, broiling and poaching. You can marinate swordfish steaks in just about any liquid or wet mixture you like, provided it contains an acid such as citrus juice, tomato juice, wine or vinegar. There is a nearly endless array of recipes available for swordfish marinades, but the basic procedure is the same for all.
Prepare a marinade in a glass baking dish according to a chosen recipe. For a basic preparation, use a cooking oil mixed with lemon juice, salt, pepper and other herbs or spices to taste. Red or white wine works as well, with some fresh or dried herbs, such as rosemary or thyme. Mix the juice of 2 lemons, 2 limes and 2 oranges for the base of a citrus marinade. Try cilantro, mint, sage or tarragon for complementary flavors. Use salsa as a tomato-based marinade for swordfish.
Lay the raw swordfish steaks in the glass dish, let them soak up the marinade for a minute, then flip them over. Cover the dish with plastic cling wrap and put it in the refrigerator.
Soak the swordfish in the marinade for anywhere from 1 to 12 hours. The longer the fish marinates, the more intense the flavor that will be imparted to the meat.
Turn the swordfish steaks over in the marinade a few times at even intervals throughout the steeping time.
Discard the marinade the raw swordfish soaked in. Prepare a separate batch if you intend to use it as a baste or topping.