Generally, no, you cannot sue unless you have some damages or some financial harm. And then the suit is not for false advertising, but rather fraud. If you worked in the shop, and knew about the sauce deception, even helped to perpetrate it, then you are not likely to get far with a lawsuit. Trying to sue a former employer could also open you up to the possibility of being counter-sued. This could all get very expensive, messy, and ultimately would not be likely to get you the satisfaction that you are seeking.
For false advertising, your better action would be to investigate possibly filing a complaint with the Bureau of Consumer Protection at the Federal Trade Commission -- see http://www.ftc.gov/bcp/index.shtml
You may also see about filing a complaint with Utah's Division of Consumer Protection at --
This answer or response should not be considered legal advice, and does not create an attorney-client relationship. If you have further questions, I would be glad to discuss your situation further. I can be reached at US - (801) 746-6300, or online at -- http://www.lewishansen.com/attorneys/robinson.html
Technically anyone can sue anyone anywhere anytime for anything. If it is frivolous, you may end up dismissed and sanctioned and have to pay your opponent's expense. You need to have a legal controversy and a reasonable basis to assert a claim. How are you hurt by their false advertising? You need damages. You cannot self-appoint yourself the false advertising police for purposes of revenge. On the other hand, you might alert the agencies that do police advertising. The FTC, BBB and state AG and perhaps your local prosecutor might take an interest, although this does not sound like much of a case. You might also alert the legal staff at the saucemaker, who would have a claim if someone is falsely describing goods with their trademark.
I am not your lawyer and you are not my client. Free advice here is without recourse and any reliance thereupon is at your sole risk. This is done without compensation as a free public service. I am licensed in IL, MO, TX and I am a Reg. Pat. Atty. so advice in any other jurisdiction is strictly general advice and should be confirmed with an attorney licensed in that jurisdiction.
You would not likely be successful with such a suit. The claim is actually not yours to make, but rather Utah's attorney general. http://attorneygeneral.utah.gov/against_fraud.html
For a free consultation related to medical malpractice, personal injury, workers' compensation, social security disability or nursing home abuse, please contact Lowenthal & Abrams, PC at 1-800-876-5299. I am licensed in Pennsylvania, but members of my firm are licensed in Pennsylvania, New Jersey and New York. This post is not legal advice, but instead contains general educational information. Please do not act or refrain from acting based upon what you read in this post. Also please remember that this post does not form an attorney/client relationship between you and me. If you have specific legal questions, you should contact an attorney in your state for assistance. I am licensed to practice law in the state of Pennsylvania.