I have my tickets for the play (booked directly through their site), and I have reserved a room in nearby Garmisch. My question now is where to get dinner during our 2 hour break?
If you go to the official website,
https://www.passionsspiele-oberammergau.de/en/visit/info-service
Click on the subject: WHICH OPTIONS WILL THERE BE FOR THE 3-COURSE-MEAL?
You'll see a link to a pdf with a list of restaurants and phone numbers. Make reservations well before your performance day.