Surprised no one mentioned packets of tuna! I pick these up at my local Safeway. Some are already seasoned---check the ingredient list, obviously. I usually get the plain ones. I travel by air frequently, several times a month, and tuck one or two into my wheeled carry-on for longer flights. Have NEVER had TSA security question me. (Remember to bring a plastic fork!) I also have a tiny bottle half ounce bottle of balsamic vinaigrette that saves me when I pick up an airport salad on the go. You can never be sure of what's in packaged airport salad dressings.