The first thing everybody needs to know is Casino Supermarket in Brazzaville. - Anything under the sun that an expat or visitor would want for there stay/tour/party. The beer and drinks selection is amazing, as is the general stock of food from around the west and Asia. Very impressive.
There is good and healthy Chinese food at Osaka Restaurant, in Pointe Noire. The average price for a meal was US$12-18. All meals were served in nice clean dishes, the restaurant is indoors and has AC, with a back-up generator, just in case. Some of the workers speak English and French.
There are several great restaurants in Brazzaville. Any taxi driver can take you to one of these nicer places 5000 - 15000 CFA. Most places are closed on Sundays. Expect beers to be overpriced here 1000 to 2000 CFA.
Noura Lebanese and Mami Wata everything are as of 2013 the best places to eat in Brazzaville. Really great and generally $10-20 for a meal all-in.