If it would be only one thing that connects Belgium and Germany, then it would be the love for potatoes. Pommes Frites are kind of a national dish and in Belgium they’re a bit special: fries are always fried two times and served with a wide variety of sauces. You would typically not order them only with ketchup or mayonnaise (like in Germany) but rather with sauce andalouse, brazil, samourai or tartare.
The origins of this dish date back to a year in the 17th century when not enough fish was available. The Belgians were frying their fish and as they hadn’t enough, they fried potatoes. Tadaa, fries were born. The best place to enjoy them in the Belgian capital city is the Maison Antoine on Place Jourdan (pretty close to the European Commission), founded in 1948. There are always long lines in front of the free-standing eatery which might serve as a quality proof. You can sit down in the restaurants around and order a drink for your fries.
Place Jourdan 1
1040 Etterbeek (Bruxelles)