Pierogis, whose name comes from the Russian pirog, meaning pie, are small, half-moon-shaped pastries stuffed with a savoury filling. They look a lot like Chinese potstickers, and there has been some speculation that the Mongols introduced them to Eastern Europe on one of their periodical bouts of western warfare; but, as Alton Brown is quick to point out, stuffed pastries appear in nearly every culture (wontons, ravioli, Cornish pasties) and their origin is impossible to trace. On our recent trip to "England’s best Polish supermarket," Mleczko, which happens to be across the street, we bought "pierogis ruskies," filled in this case with dry cottage cheese, potato and onions (the ingredients list laboriously translated word for word from online sources - ah, the marvels of the modern age!). They're traditionally sauced with butter, topped with fried onions and bacon, dolloped with sour cream and served with borscht or as an accompaniment to another kind of soup. Our pathetic non-Polish arteries couldn't quite face such an onslaught, so we opted for a marginally healthier approach; still sauced with butter, but accompanied with a salad of mixed greens and thickly sliced red onion, tossed with olive oil and white wine vinaigrette. This turned out to be a magical combination; the sharpness of the greens and the crunch of the onion provided a splendid foil for the bland, cheesy richness of the pierogis. As a final touch, we topped them with sour cream and authentic Polish horseradish (pictured here with a photogenic interloper), just to give them a little kick.