I'm relatively new to Cambridge, and I'm looking specifically for Hunan-style Chinese restaurants, anywhere from Boston to Waltham to Lexington and all areas in-between. I've come here from the San Francisco area where I could practially trip over them ...
Good luck. Let me know if you find one. I've spent a lot of time in Changsha (capital of Hunan province) and I've yet to find anything that even comes close to Hunan food in the states, even in San Francisco. I attribute it to two things:
1) Lack of good, hot green peppers, a Hunan staple. Anaheims or Hungarians come close, but do not have the thin skin, hotness, and richness of Hunan green peppers.
2) Lack of authentic Douban (spicey black bean sauce). Yes, you can find the bottled stuff everywhere in the states, but it isn't from Hunan. I've found something close here in Seattle, but never found it in Boston when I lived there.
I think there are a lack of good Hunan restaurants here because there are not many Hunanese in the US and a lot of urban Chinese consider Hunan food to be peasant food and not worthy of eating in a restaurant. This is too bad because Americans really tend to like Hunan food since it is VERY savory and greasy.
If you like Hunan and Sichaun food and have not been to Hunan or Sichuan, I think it is worth going there just to eat. One thing I have never found here is Qiezi Bao (loosely translated as "Eggplant Cassarole" or "Eggplant Pot") or steamed bread filled with pork, fermented balck beans and hot, green peppers. Heavanly! And don't get me started on Sichuan food.....