When it comes to eating in Dong Xoai, you can choose between Vietnamese, Vietnamese and Vietnamese. There are no English-language menus anywhere that we are aware of. If you don't speak the lingo, some sort of Vietnamese culinary phrasebook is in order.
You'll find plenty of small restaurants in the area around, but not inside, the central market. Dona Beer is about 1.5km east of the roundabout, just before the Incom Bank, and sets itself apart by offering fresh beer in plastic bottles (almost bia hoi) and some very tasty dishes to accompany it. It's a point and pick situation, but we had the luon xao lan (sauteed eel) which was excellent, and cut chien gion, which is some sort of small game bird, breaded and deep fried -- more flavourful than chicken, and it satisfied that KFC craving better than the real thing. (Don't eat around the heads -- they're the best part.)
Several places offer very similar, very standard Vietnamese fare south of the roundabout. Ba Hai Sap Nha has a bit of a garden atmosphere to it, and spots like Thuy Tien, Huong Bien, and Tay Nguyen out by the bus station come recommended by locals. If you can find Le Quy Don St, which branches from Phu Rieng Do St (Thinh Lo 14) about a kilometre south of the roundabout, head west a couple hundred metres to where you'll see a sign for the turnoff to Phong Dinh, which specialises in grilled wild boar.
Ba Hai Sap - 878 Phu Rieng Do St. Dong Xoai. T: (0651) 879 404.
Dona Beer - 588 Route 14 (Quoc Lo 14) Dong Xoai.
Huong Bien - Phu Rieng Do (near the bus station) Dong Xoai. T: (0651) 883 897.
Phong Dinh - off Le Quy Don St. Dong Xoai. T: (0651) 884 198.
Thuy Tien - Phu Rieng Do St. Dong Xoai. T: (0651) 899 802.