Eating options at the tunnel sites themselves are limited. The canteen at Ben Dinh serves simple food and is useful if you are hungry after the tour, but it is functional rather than memorable. Ben Duoc has similar basic facilities. The serious eating is in Ho Chi Minh City — most visitors are better off having a good meal in HCMC before heading out, or saving their appetite for the return.
Cu Chi town, the district centre about 10 km from Ben Dinh, has a range of local pho shops, banh mi stalls, and com binh dan (rice plate) restaurants along its main streets. These are cheap, genuine, and worth exploring if you are spending a full day in the area rather than rushing back to the city.