Slightly different query, but what would you veterans of Brussels and Rotterdam recommend by way of eating?

This is really a two parter question, because I'm happy to try out that tiny corner cafe in an obscure part of the city that does the perfect Andean burrito (or gives you crippling food poisoning) or great Ethiopian cuisine, but I'm also interested in the better chains. Any particular ones that tend to be open late and do reasonable stuff?

There's always the well known international stuff like McDonald's, but I'd rather try a place that does a good Belgian waffle or what have you than eat what I can have in the UK. I've had good results eating at the Old Dutch Pancake House in Amsterdam previously, I was wondering if there were any popular chains like that, or good food markets people might recommend?

There's an excellent cafe outside Antwerp Centraal. As you leave the station keep walking. You'll see a main road on the left walk past that and the cafe is there on the left hand side too. Sells all sorts of Belgian food.

Two very good restaurants in Brussels in the mid-range price that serve classic Belgic cuisine:
Fin de Siecle, beer-braised beef
Chez Leon, anything mussels

And for the basics:
Maison Dondoy, waffles
Fritland (or any street corner), pommes frites (hey, they invented them)

I lived in Rotterdam for about a year. Here’s my go to eats:

Warung Mini on witte de withstraat. The best chicken sate you’ll ever have. Huge portion. Only 13 or so euro.

Mac elaviv on Coolsingel. My go to for turkse pizza. Great doner. Cheap.

Cafe dudok. Proper Dutch cafe. Great apple tart.

Locus Publicis. No food but one of the best beer bars in Holland.

Cafe Bazaar on witte de withstraat. Food is good to decent but great ambience. Good date spot.

Awesome guys, thanks to everyone who replied here. I'll post a trip report when I get back later in June with my compliments.