Sorry the way I read your post I thought you did not know if it was 28 or 35. Why do you have such a difference in food cost from month to month? It might be fun to graph out monthly food costs and events.
Food cost between 28 and 35 percent and you are doing a million a year? That is 70000 dollars a year unaccounted for. If I were the GM I would say get your pencil and paper and figure out where the money is going. Food cost too much work, what were you hired for setting pins?
Grits and polenta are not the same. Grits are made from hominy. For Shrimp and grits I use shrimp stock as the liquid base for the gravy. Red eye gravy is made by pan frying country ham then adding just a little sugar to the pan drippings and deglaze with strong black coffee. This is served over biscuits or grits.