There are numerous restaurants in Huacachina, all of them overpriced when compared to normal Peruvian prices.
The Casa de Avinoam, the restaurant located in the Carolas del Sur Hostal, has delicious thin-crust pizzas. Pizaa prices range from about $6 USD for a personal pizza to $15 for a large family-sized pizza.
The restaurant at Desert Nights Youth Hostal is quite popular too.
For those craving tasty ethnic food, head to Bamboo Cafe, located in a small lot in between Carola del Sur and Hosteria Suiza. They serve a flavorful Thai curry, decent falafel popular with the Israeli and Arab travellers, and other ethnic and peruvian dishes. The Bamboo Cafe is also a great retreat for those who have been travelling for months and are in need of a bacon butty with brown sauce, marmite or a full English breakfast.
In Ica, there are quite a few decent restaurants. One of these is the restaurant "El Otro Peñoncito" which has a very pleasant, upscale decore and serves a variety of italian and peruvian dishes. It is slightly expensive by Peruvian standards, unsurprising since much like the restaurants in Huacachina it exists to serve food to tourists.
A great, cheap restaurant to eat lunch is McGrille, on Avenida Cutervo. It has cheap but tasty menus at lunch time from around 12:40 to 3:00pm that only cost 7 soles per person during the week and 9 soles on weekends and holidays.
Valentino's Cafe-Bar, across the street from McGrille, has tasty fixed-price lunches for 9 soles and free WIFI for customers. The lunches here will be higher quality than similarly priced lunches in huacachina.
