I ate at Tallgrass last year, and it was the very best meal I had in all of 2007; it was absolutely wonderful in every way. You can read my complete, detailed report, including descriptions of the items we had, in
this topic.
Oh, and no matter what you do, check out the men's room (even the women in your party - it's the one-person type, no worries).
Have a GREAT time!!!