They do have a sign on a pole, at the road that passes Osteria Dei Cavalieri, but it is the only thing showing the narrow drive-way.
So it's a well-hidden gem of a restaurant.
Recently the Osso Buco alla Milanese from Osteria was named the best and most authentic one in Belgium. And it is very good. Very tender meat, and the sauce has the thickness you only get from simmering it long enough.
The Paella is definitely also recommendable.
The owners is an Italian couple.
You'll meet her in the restaurant, and she's behind most of the cooking/recipes. The husband is reportedly handling the pizzas they also have on the menu. Though I think most of those are sold as take-away.
They have a couple of sons that also have restaurants in nearby cities, so you can guess where the sons learned to cook.
The owners are engaged in exchanging things like gastronomy between Lombardy and Limburg. You can visit their website to see more of that and of the restaurant.
We've been at Osteria several times and we have never been disappointed by neither the food, nor the wine they have served.