You should be able to find some good New Mexican food, as well as Tex-Mex, BBQ, Steak houses, etc. roughly along that route, though at least for the Texas part I would suggest trying to get off the interstate highways and explore some of the smaller Texas towns, many of which are home to unique food items. Unlike much of the US Texas was settled in the mid to late 1800's by mostly European immigrants, settling into towns that even today retain some of the heritage of the "old country" This might be German heritage in Fredericksburg or , or Polish settlers in Brenham or New Waverly, Czech settlers in West, La Grange, Schulenburg, etc.