A group of us tried the Gristmill because we heard food was good and a great atmosphere. Definitely pretty to be under trees and to look out over the river. Problem is that we didn't realize this restaurant is completely "open aired" and when temperature is a humid 102 degrees at 6:00pm, this does not make for a good dining experience. When asked to be seated indoors, we were unaware there was no a/c and would placed in a section that had no breeze except for the overhead fans. Outdoors did not seem to be particularly cooler and there may be sections with more of a cross breeze but we didn't know the layout of this huge restaurant well enough to know where to be moved. So we stayed put and sweated.
Portions of certain items were certainly large enough to share such as onion rings and their entree sized salads but IMHO the fried catfish entree itself was really adequate for just one. For the above items, prices were quite reasonable for the size of the portions. I had the side spinach salad (for an extra $4.99) but the size of that side was huge and could have easily have been shared.
If ever back in Gruene in cooler weather I would like to give this place another shot.
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