Brussels near Sheraton Hotel
You could try Les Dames Tartines on Ch de Haecht, perhaps 10 minutes by foot just by the Botanique. It's a long established franco-belge style place with a decent wine list.
A bit further away is Sense Nome in Rue Royale Sainte-Marie - Italian, has (had?) a Michelein star - very good but a bit more expensive.
4a Calle Oriente 1C, Antigua, Sacatepequez , GT