Soupe aux Grenouilles de la Meuse

The soupe aux grenouilles (frog soup) of the Meuse valley is one of Lorraine’s most delicate and distinctive preparations: a velvety cream soup studded with tender frog’s legs, flavoured with garlic, parsley, and a splash of Riesling, that represents the region’s long tradition of freshwater cuisine. The Meuse river and its tributaries, along with the countless ponds (many created by monastic orders for Lenten protein), have provided frogs for Lorraine’s tables since at least the medieval period. The frogs’ legs (cuisses de grenouilles, sold cleaned and paired) are first soaked in cold milk for 1 hour to whiten the flesh and mellow any residual marshy flavour. Meanwhile, the soup base is constructed: a white mirepoix (onion, leek white, celery) is sweated gently in butter without colour, a tablespoon of flour stirred in to form a white roux, then chicken stock and a glass of dry Riesling are added gradually, whisking to produce a smooth velouté. This simmers for 20 minutes while the frog’s legs are prepared: drained, patted dry, and sautéed briefly (2 minutes per side) in foaming butter with a minced garlic clove until just firm. The meat is then picked from the delicate bones (each leg yields two tiny morsels of pearl-white flesh) and reserved. The bones are added to the simmering soup for an additional 10 minutes of flavour extraction, then the soup is strained through a fine sieve, returned to the pot, and finished with 150ml of crème fraîche and 2 egg yolks (the classic liaison). The picked frog meat and a generous chiffonade of flat-leaf parsley are added at the last moment, the soup barely brought to temperature (never boil after the liaison), and served in warm bowls with croutons fried in garlic butter. The soup should taste of fresh, clean cream with a whisper of garlic and the gentle sweetness of frog, which resembles a cross between chicken and the finest white fish.