Where to go for a traditional Sunday roast in Brussels?

I have been to Oreillys, the quanty and quality seems to be decent

http://oreillys.com/brussels-menu.html

deValera's is a good one. They also do a relatively traditional Fish and Chips!

http://www.flagey.eu/

You can get that menu for half price by leaving Belgium. Not that the tax free brigade would consider it