- 2 3/4 pound veal breast (bone in)
- 1 pound boneless veal shoulder, trimmed and cut into 2-inch pieces
- 2 1/2 quarts water
- 6 fresh parsley sprigs
- 2 fresh thyme sprigs
- 1 bay leaf (not California)
- 4 black peppercorns
- 2 onions, halved
- 4 carrots, quartered crosswise
- 1 leek (white and pale green parts only), halved lengthwise and cut crosswise into 1/2-inch pieces
- 2 tablespoons unsalted butter
- 1/2 pounds mushrooms, quartered
- 3 tablespoons unsalted butter
- 3 tablespoons all-purpose flour
- 2 large egg yolks
- 2 tablespoons crème fraîche
- 1 1/2 tablespoons fresh lemon juice
- Cut meat away from veal breastbone, reserving bone, and cut meat into 2-inch pieces.
- Bring veal breast and shoulder, veal bone, and water to a boil over moderate heat in a 7- to 8-quart heavy pot, skimming froth. While water is heating, wrap parsley, thyme, bay leaf, and peppercorns in a small square of cheesecloth and tie into a bundle to make a bouquet. Add bouquet garni and onions to pot and simmer, uncovered, until veal is tender, 1 1/4 to 1 1/2 hours.
- Preheat oven to 300°F.
- Transfer veal with a slotted spoon to a heatproof serving dish and keep warm in oven, covered with foil.
- Discard veal bone, onions, and bouquet garni, then pour stock through a fine sieve into a large bowl. Return stock to cleaned pot, add carrots and leek, and simmer until tender, 10 to 12 minutes. Transfer vegetables to serving dish. Boil stock until reduced to about 2 1/2 cups, about 10 minutes.
- While stock is reducing, heat butter in a 10-inch heavy skillet over moderate heat until foam subsides, then cook mushrooms, stirring, until just tender, 6 to 8 minutes. Transfer to serving dish and season veal and vegetables with salt and pepper. Keep warm in oven.
- Melt butter in a 2- to 3-quart heavy saucepan over moderately low heat, then stir in flour. Cook roux, stirring, 3 minutes (do not let brown). Whisk in reduced stock and simmer, uncovered, whisking occasionally, 15 minutes. Whisk together yolks and crème fraîche in a small bowl, then whisk in 1 cup sauce. Whisk yolk mixture into remaining sauce with lemon juice, then cook over moderately low heat (do not let boil), stirring constantly, until it reaches 160°F on an instant-read thermometer and coats back of a wooden spoon.
- Season sauce with salt and pepper and pour over veal and vegetables.