A local told us about the Tune Up and we went to give it a try. Even in the height of tourist season, there want a wait but the tables are catch as catch can because you order at the counter. Some people who hadn't ordered had already claimed tables so it took a minute for us to find a seat. (Insert here my opinion of parties of two who claim a four top when the place is clearly crowded. Your purse can go on the floor, dear.)
The service is casual but attentive and everything arrived together and as ordered. The food has a nice Peruvian twist but with the excellent sauces one expects in NM. Try the tamales, which have potatoes inside!