A Euro-style café run by Belgians, Via Via Café (tel. 504/651-4652, 7 a.m.–10 p.m. daily) is one of several in a network of travelers’ cafés around the world. They serve reasonably priced breakfasts and light meals, always with several vegetarian options, like veggie burgers and pasta, and countless daily specials, often based on Asian cuisine. Indonesian nasi goreng has been one of the specials. Breakfasts run US$2–3, while most lunch and dinner dishes are US$3–5. There are also a couple of inexpensive rooms for rent in the back, and the bar is frequently full of travelers in the evening.
Run by a British expat named Tanya, 
Twisted Tanya’s (www.twistedtanya.com [1], 3–10 p.m. Mon.–Sat.) offers creatively prepared courses like curry shrimp, conch soup, or Chinese dumplings with wasabi for US$13 a plate, plus delicacies like cheesecake for dessert (you can order à la carte or pay US$18 for a three-course meal). There are always a few vegetarian choices on the menu, and a three-course backpacker’s special is available 4–6 p.m. for just six bucks. The restaurant, a block south of the municipal market, is also a popular spot for happy hour.
Jim’s Pizza (11 a.m.–9 p.m. daily), a block south of the parque, cooks up an acceptable, shareable pizza (US$7–9) as well as tasty wood-fired rotisserie chicken and burgers.
Pícame, on the road heading out of town toward the ruins, is a great little joint with the best roast chicken in town, rice and veggie options, and renowned burgers, all at fair prices.
Links:
[1] http://www.twistedtanya.com