I professed my love for Bia Mara before . For us, no trip to Brussels goes without eating here. Cheap and OMG good. After you have their gourmet fish and chips you will be hooked. Try it with minty mushy peas or garlic truffle sauce, home made tartar sauce or chorizo beans. It's a treat for just 10 euro a portion. Everything is fresh and sells fast. Menu changes all the time, depending on what fish is available. Some days they are only open a few hours due to selling all the food. The specials of the day sell fast too. YES! they are THAT good. But don't take my word for it, go check it out.
The only downside to Bia Mara is how small the restaurant is. People often wait in line to be seated. Again, it's THAT good. Also I will mention that it's an English speaking place and the menu is in English.