Like many regions of Indonesia, Tana Toraja has its own distinctive foods. However, the foods of Toraja are a little more different than most, due mainly to the fact that the vast majority of them are Christian. So, you have such delicacies as braised pork blackened by a special spice found only in Toraja, washed down with some palm wine. Other delicacies include meat (usually chicken) cooked in bamboo, and coffee.
Unfortunately, there are very few restaurants outside of hotels in Tana Toraja. There are stalls and small roadside eateries catering mostly to locals, but these are generally only for the 'hygienically adventurous', as one guidebook author puts it. The one restaurant that seems to serve local foods to foreigners is Celebes, located a little north of Rantepao.