TIP:
To clean the shells for stock, split them in half lengthwise with a knife. Pull out and save the coral (the ovaries and egg sac, which looks like a long, thick green-black vein), if desired. Some female lobsters will have no coral, depending on the season. Coral must be used the same day. Discard the tomalley (liver) and grain sac. Use shears to cut up the shell and legs into 1 1/2- to 2-inch pieces.