Pappasito's + 3
I'm from Houston but have been living in Little Rock for the past year (aka - apparently too far north for good mexican food) and ate at the DFW Pappsito's last time I went through there, I was so surprised at how good the food was there, pretty much restaurant quality.
Gate guru app will show you every restaurant by terminal in a given airport, handy for finding something to eat wherever you're flying through