Ars Vinorum is a wine bar / restaurant located on a 60-meter long street right behind Porte de Namur (rue de la Reinette 6, 1000 Brussels, Tel: 02/ 503 39 33). I went to this restaurant following some very positive recommendations, but was a bit disappointed because even though the food is good, there is much better in Brussels.
This Italian-owned restaurant is small (about 12-14 tables) and has a nice decor, with wine bottles lining the walls and dining room. The menu changes twice a week, offering a selection of pasta dishes, meat, fish, and risotto, and each dish comes with a wine recommendation, which makes decision making much easier and allows you to try wines you otherwise might not have chosen. The dish-wine pairing up is quite good, so I would recommend going for their suggestions unless you are a true wine connoisseur.
The food is overall good and prices are reasonable (between EUR 15 and EUR 20 for the main course, including a glass of wine). However, the food is not exceptional and for the same price, you can have a much better meal at other Italian restaurants such as Il Pasticcio.
Ars Vinorum is open for lunch (11-13h) and dinner (19-23h) during the week and for dinner on Sunday evenings. I would recommend it for a nice, casual meal with friends, but probably as a second choice if other options are already booked.