Consider investing in reusable compartmentalised trays and crockery instead of disposable ones. If you contract your canteen, take a look in the General section at the "Choose sustainable food service contractors" solution.

Use dispenser for sauces, soft beverage, ice cream, coffee and tea instead of single dose packaging. Allow self service for napkins, bread, sugar, etc.

If reusable is REALLY not an option, consider using compostable dining ware suitable for a food waste digester if used. Otherwise, use disposable ware with first lower carbon footprint and then from sustainable sources