Most of the time a chef has to think outsie the box to come up with a menu idea, but in this case you have to start within the box of your restaurant's niche. Start simple - instead of your usual band of standards, throw a native or wild element in - say Duck or Goose Cacciatore, and the sauce having a squash or tuber element? Your Wellington? Why not Buffalo or Elk or Moose. Then your research needs to kick in, for example, one of the native peoples south of us were famous for the HUGE shellmounds of oysters and clams they left behind - and there's TONS of stuff you can do with seafood. We once played with an acorn flour breading, as that's also a staple of the historic native diet out here. It wasn't very successful (it's difficult to leach enough tannin out of it to make it work), but it was a fun project.
Here's the rub. Select an area. Look at the peoples who populated an area, their cullinary tastes, what they ate, build a recipe on that, and then also present the STORY of the dish, what your insporation was, what areas those ingredients were popular or "everyday food" was. You can twist it around to make a "western" dish from "native" foodstuffs... but since that's the wasta of your shop, you need to make sure you atill stick to what your restaurant is all about.