Wikitravel's Bhutan entry. This site seems to be updated on a regular basis and has a good list of restaurants in the major urban areas. The only drawback is the wiki format which doesn't exactly make it easy for you to find this quickly.
Really appreciate YANA's professional organization of the entire trip. Could not imagine how a trekking trip could such be well organized - more or less like a 5-star hotel with the only difference of we were at more than 3,000 above sea level. Special thanks to Yeshey and the chef who had given tons of assistance when I was descending due to attitude sickness. - Simon Liu, Hong Kong