Not knowing whether your employee participates in a health plan or not, I can only tell you what we had and what we did for our employees with problems. Many larger health insurance companies provide addiction treatment and services as part of their plans. If your employee participates, the first thing you or your HR person want to do is to contact the insurance company and find out if these are provided, and whether the employee will need a physician referral to use these benefits.
Then have the private talk with the employee.
You have certain rights as an employer, based on the safety factor for the other employees in your kitchen. Find out what your rights are in your state.
Theresa