If you are up just north of Houston, in The Woodlands, there is an excellent grass-fed, gluten free restaurant called The G's (www.thegs.net/). Not too pricey, and the desserts are phenomenal. Good place for breakfast on weekends, lunch and dinner otherwise. My favorites are the corned beef hash for breakfast (corned beef is shredded, not ground), and either the buffalo tacos or grilled chicken and portabella salad.
Ibeza offers a grass fed tenderloin at lunch, Ibiza @ 2450 Louisiana St. Houston, TX 77006 713.524.0004. It is pricey. http://www.ibizafoodandwinebar.com/lunch.pdf Although I have not had this selection as of yet, I had the lamb shank.
I have not made it to Feast yet but I hear that it is quite good and they list the sources of the meats on the menu and the website weekly. http://sites.google.com/site/feasthouston/ 219 Westheimer Road, Houston, TX 77006 713-529-7788 I am dying to get over there and would have liked to try the pig nose & parsnip soup yesterday.
One failsafe in Houston is to go for gulf seafood. The Pappa's chain is somewhat reliable but if you can get down to Kemah or Seabrook to eat you can get fresh gulf seafood, especially shrimp as this is where many shrimp boats come in. On one side of the Kemah bridge are most of the restaurants, on the other side the boats pull up to the docks where the seafood mongers are located. -TPSW-