I'm not a professional cook by any means.I just play one at home.
What comes to mind is
Onion Rolls,can be made ahead of time,and toasted when you need them.
Jazz up the tomatoes with some Italian Seasonings.Checca? Diced tomatoes with fresh garlic,basil,olive oil,sea salt.Tomatoes are in season and relatively cheap to get right now.
Play with the mayo,add a little garlic paste and blend,with some freshly diced Sweet Red Bell Peppers.Those to are in season.
Instead of Mozzarella,how about Provolone,Monterey Jack..