The Yucatan Base Camp Grill serves up a variety of barbecue-style dishes. They've improved their menu over the years, and there are some tasty and satisfying items on the menu. I particularly like some of the interesting side dishes they offer. As a bonus, the food is probably a bit healthier than the pizza and fried foods you find at a lot of places around the Park.
There is some outdoor seating and the atmosphere out there is exceptionally relaxing, so I would recommend getting a table outside if the weather permits.