1. Make sure all of your branded stuff (Napkins, cups, etc) are all done with Pixel Art.
2. One popular thing restaurants do is get a sandwich section and call them "The Mario", which would be a meatball sub... or "The Super Mario" which is a footlong meatball sub. Y'know, stuff like that's cool.
3. A turkey leg, Mike Haggar's Favorite.
4. In San Antonio, TX there's a place called "Aztec on the River" - They sell fried jalapeno peppers stuffed with sauteed chicken, bell peppers, onion and cheddar cheese. Call em Maru Balls or something (Metroid treat.)
4a. OH! Wait... if you can submerge some cherries inside of green jello, you can have a Metroid dessert!
5. Have a mini-menu for Sushi... stuff's inexpensive to produce, but sells for a high markup. You can have it themed around Cooking Mama, because not only does she give me an erection... she gives me the munchies
6. Appetizer Sampler - Confirmed for Brawl. Just saying.
7. Possible problem: Pizza. Can you credit Ninja Turtles as video game characters? I mean, they're mainly TV/film for me... but they've done a TON of games over the years.
8. With food coloring, it would be possible to simulate the red-cap and green-cap mushrooms of Mario Brothers. When asked, say they're magic... but while under oath, claim they're ordinary mushrooms and not intended for children under 17.