Veal Blanquette

In a large, shallow dish, combine the veal, milk, thyme and bay leaves. Cover and refrigerate overnight.

Remove the veal from the milk and pat dry with paper towels. Reserve the thyme and bay leaves. In a large saucepan or pot, melt 1 tablespoon of the butter in 1/2 tablespoon of the oil over moderately high heat. Add half of the veal, season with salt and pepper and cook until browned, about 3 minutes per side. Transfer the veal to a large plate. Repeat with 1 tablespoon of the remaining butter and the remaining 1/2 tablespoon of oil and the remaining veal.

Add the onion, carrot and celery to the same pan and cook over moderate heat until softened, about 5 minutes. Return the veal and any juices to the pan. Add the Cognac and simmer over moderately high heat, scraping up the browned bits from the bottom, about 1 minute. Add the wine and simmer until reduced by half, about 4 minutes. Add the cream and 3/4 cup of the water and bring to a simmer. Tie the reserved thyme and bay leaves and the parsley sprig into a bundle and add to the stew along with the mushroom stems. Cover and simmer gently over low heat until the veal is tender, about 1 1/4 hours.

Meanwhile, in a medium saucepan of boiling water, cook the pearl onions in their skins over moderate heat until tender, about 5 minutes. Drain and peel the onions, leaving them whole.

In a large skillet, melt the remaining 2 tablespoons of butter over moderate heat. Add the mushroom caps and season with salt and pepper. Cover and cook for 5 minutes. Uncover and cook, stirring occasionally, until browned, about 5 minutes. Transfer to a shallow bowl. Add the remaining 1/4 cup of water to the skillet and simmer for 30 seconds, scraping up the browned bits from the bottom of the skillet. Pour the mushroom liquid into the stew.

Using a slotted spoon, transfer the veal to a bowl. Strain the sauce, pressing on the solids to extract as much liquid as possible. Return the sauce to the pan. Put the egg yolks in a small heatproof bowl and whisk in 1/4 cup of the hot sauce, then whisk in 1 cup of the sauce. Whisk the egg yolk mixture into the sauce in the saucepan and cook over moderately low heat, whisking constantly, until just thickened, about 5 minutes; do not boil. Add the lemon juice, veal, pearl onions and mushroom caps and season with salt and pepper. Rewarm the stew over low heat, stirring; do not let it come to a boil. Spoon the stew into bowls, sprinkle with the chopped parsley and serve.