In addition to what Cornelius said, PMI Project description is clear. If you are developing a new product following the project management processes yes you can apply. But in the normal circumstances, restaurant activities is considered as routine job or operations activities because repetitive. It is up to you to identify if you have done can be considered as project. Remember a project is an temporary endeavor to produce a unique product. So unique product or service within a specific time with a budget and resources.
You have to determine this yourself. Please take a look at the PMP Exam Content Outline, which you can find at
. Pages 5-10 describe all the tasks that PMI expects you to have been in charge of as a PM and those tasks are also the basis for the PMP exam.
So if you can honestly say "yes, I was leading and directing MOST of these tasks on my projects" then you are good to go.