Sao Joao is a local restaurant and bar located at the end of the Che Guevara street, in front of the car rental Avis. It is partly open-air and surrounded by plants and trees so it is quite relaxing and nice for a drink. When we went there, in the end of the afternoon, the place was not so busy. Patrons were mostly regulars reading their newspaper or watching a football game.
It is rather expensive: from 2300 kwanzas to 4000 kwanzas for a dish (fish or meat). The food is good but not impressive since it is similar to what we can get pretty much everywhere: A mix of Angola and Portuguese dishes cooked and presented in your plate just as you could expect to have it served at home.
Conclusion: Recommended if you live nearby because the setting is nice but food a bit pricey. Good service.