Italian filmmakers created the genre of the Spaghetti Western. That makes “The Drop” an Amstel Eastern. The cast and crew of this New Jersey mob movie hail from the mean streets of Belgium, the land of waffles, chocolate and blonde beer (director Martin R. Roskam, cinematographer Nicolas Karakatsanis and co-star Matthias Schoenaerts). To fill other roles, they reached out to North Sea neighbors