The major tourist sights — the National Museum, the carpet museum, the monument complexes — are clustered along Archabil Avenue and the parallel ministry boulevards, but the eating options immediately around them are thin. Most visitors end up lunching at their hotel or at a restaurant their guide selects. If you have more freedom, the area east of the old city centre, around the bazaar on Teke Street and the residential streets behind the Russian Orthodox church, yields small restaurants and chaykhana where the food is local and the bill is very low.
One category of establishment worth knowing about is the stolovaya — the Soviet-era canteen, still functioning in modest form in some residential neighbourhoods. These serve set meals from a counter: a bowl of soup, a plate of plov or a meat main, bread, tea. No menu, no decisions, and an authentic encounter with the post-Soviet domestic food culture that underlies the marble exterior. A full lunch will cost less than a dollar at the official exchange rate; somewhat more if you are exchanging on the street (which carries legal risk).
The hotel restaurants serve alcohol; ordinary restaurants mostly do not. Breakfast at most mid-range and upmarket hotels is a buffet combining Turkmen flatbreads and cheeses with a Soviet-style spread of cold meats, tinned fish, and strong tea. It is filling and sets you up for a morning of monument-visiting.