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Puree of Potatoes, Lucernoise
Finely slice a half-pound piece raw lean veal from a shin, two ounces raw ham, two white onions and three leeks, place in a saucepan with an ounce butter and fry on fire for ten minutes, stirring once in a while. Add six large, peeled, sliced raw potatoes with two branches parsley, one branch chervil and two bay leaves. Moisten with half gill white wine, quart and a half broth and quart water, season with a teaspoon salt, half teaspoon pepper, lightly mix and let boil for ten minutes. Cover pan and set in oven for an hour and thirty minutes, remove, dress puree through sieve into a basin, then through Chinese strainer into another saucepan. Place pan on a brisk fire, pour in a gill cream and half ounce good fresh butter, mix well, and as soon as it comes to a boil pour puree into a tureen and serve with a plate of bread croutons separately.
A classic French-style potato purée soup, thickened by nothing but the vegetables themselves and enriched at the last moment. Most of the work is in the straining.
- The hinge: the meat is flavouring, not fillingThe veal shin and ham are sliced thin so they give up their flavour over the long oven simmer. Most of their fibre stays behind in the sieve; the body of the soup comes from the potatoes.
- Liquid measuresA gill is half a cup, so half a gill of wine is 1/4 cup and the finishing cream is 1/2 cup. Total liquid is about 2 1/2 quarts.
- Oven heatThe original gives none. A covered pan meant to hold at a bare simmer for 90 minutes suggests something in the region of 300-325F; hotter and the liquid boils down before the potatoes surrender.
- "Chinese strainer"A chinois, the fine conical strainer. The two-stage straining is deliberate: a coarse sieve to push the solids through, then the chinois to catch fibre and leek strings. A food mill followed by a fine-mesh sieve does the same job.
- Six large potatoesRoughly 2 1/2 to 3 lb. Use a floury variety such as russet; waxy potatoes resist breaking down and give a gluey purée when forced through a sieve.
- "Brisk fire" at the finishHigh heat, but bring it to a boil and stop there. Once the cream and butter are in, prolonged boiling will break the enrichment and dull the flavour.
- Chervil and leeksFresh chervil is seasonal and rarely stocked; a small handful of parsley with a few fennel fronds is the nearest substitute. Split and wash the leeks thoroughly, grit will not strain out.
- YieldAbout 2 quarts of finished soup, serving six to eight as a first course.
"Lucernoise" means simply "of Lucerne," and it belongs to the nineteenth-century French practice of naming a purée to fix it in the repertoire, each name marking a small variation on the same technique. What distinguishes this one is the veal shin and ham cooked down into the purée itself, giving the smooth, meat-backed depth that classical kitchens prized over a plain vegetable soup. Alexander Filippini, who spent decades at Delmonico's in New York, assembled The International Cook Book from that repertoire. The double straining, through sieve and then chinois, is laborious work.