Thank you for the information and your question. I will assume, unless you tell me differently, that this employee has not signed a non-compete agreement or an agreement concerning proprietary information and non-disclosure
. If that is true, then although you can try to make him sign one now and tell him that if he doesn't he is terminated, if he is already planning to leave, that probably won't work. In other words, he will probably refuse to sign a non-compete/proprietary information agreement.
That leaves you having to react if he does leave and try to open a shop that is a mirror image of yours, or use some special process or recipe that you have. In that case, you can try to sue him for theft of proprietary information, and also try to get an injunction, but those suits are not inexpensive.
Those though are really your only options. Have him sign a non-compete drafted by a local employment law attorney now, or try to sue him in tort
if he follows through with the rumored action.
Please let me know if you need any clarification. I would be glad to assist you further if I can.