literally: “bricklayers’ jam” / meaning: Mett (minced raw pork)
Many nations have their nasty delicacies. The French have Roquefort cheese. The Mexicans have fried locusts. The Americans have pineapples on their pizzas. The Germans on the other side seem to have a strange obsession with raw meat.
Of course, you can order a “steak tartere” in other places, which is usually made from raw ground beef and associated with fine cuisine. The typical German Mettbrötchen however, an open sandwich with raw minced pork, is as far away from fancy dining as you can possibly get. It is usually sold for as little as one Euro at meat counters to physically hard-working people with high energy demands—thus the colloquial name Maurermarmelade for the meat spread.
By the way, the Mett in Mettbrötchen is cognate to English “meat.” However, that alone will hardly be enough to make this unusual specialty an international export hit.