If the squid hasn't been cleaned, gently separate the mantle (also called the tube) from the head, then scoop out and discard the interior of the mantle. If you wish to use the ink, remove it carefully from the inside of the mantle. Pull the membrane off the mantle. With a sharp knife, cut the tentacles off below the eye, then squeeze to discharge the hard beak. Rinse and pat dry.
When using prepared steaks, tenderize them by making 3/4-inch (about 2cm) deep cuts around the edges, then pound with a mallet until thin.
Squid flesh can become tough and chewy. The secret to successful squid cookery is to either cook it quickly enough so it doesn't toughen, or to braise it long enough to break down the dense, firm muscle fibers.
Pour oil into a wok or deep fryer; it should be at least 1 1/2 inches (about 3.8cm) deep, and the cooker should be less than half full of oil. Heat oil to 375F (190C), using a thermometer to monitor temperature. Cut squid into bite-sized pieces. Dip in batter, drain, then slip pieces into hot oil. Cook until crisp (about 45 seconds). Don't wait until it turns brown or it will be overcooked.
Dip tenderized squid in a beaten egg-milk mixture, then in crumbs and spices if desired. Heat a frying pan until hot and add oil. Add squid, making sure they are not crowded in the pan, and cook, turning once, until brown, about 2 minutes.
Cut squid into bite-sized pieces and stir-fry gently in hot oil for about 30 seconds before adding to your favorite stir-fried vegetables. Total cooking time should not exceed 2 minutes.
Cut the mantle into 2- to 3-inch (5 to 7.5cm) pieces. With a sharp knife, score both sides of the meat with a diamond pattern. Put on skewers to keep from curling, then place them 1 inch (2.5cm) above prepared hot coals or fire. Cook for 2 minutes on each side.
Cut squid into 3- to 4-inch (7.5 to 10cm) lengths and braise in cooking liquid and herbs and spices for about 1 hour.