EDIT: After thinking about it a bit more, maybe not all of it has to be backwards. I could still have menu items with backwards lyric-based names like "the ice cream ear", "loose heart symbol" (that counts as a food since Sarah McLachlan said to eat it backwards; maybe it could be a heart-shaped steak or something), and "down waters with night ice". I could refer to appetizers as "things to nibble on like the dinner alley bus". You'd have to pay for your food first, then type up your receipt, then you get your food, and then once you're done you have to recite what you ordered backwards (the menu will show you how). Backwards music would play on the radio. Finally, the waitresses would be dressed up as Waenya, Wadido, and Warah McWachlan and walk backwards all the time.
EDOT: Another funny thing I thought of! If you got food poisoning somewhere else, you can come to my restaurant and yell "WHAT THE (insert cuss word or euphemism here) DID YOU PUT IN OUR FOOD?! THIS IS AN OUTRAGE! YOU'LL BE HEARING FROM MY LAWYER!!" backwards and we'll cure you before you order!