This takes time and care, but is a reward in the end.
Soak the sweetbreads in cold water for 3 hours, changing the water every now and then, until any blood has drained out. Then put them into a saucepan and cover with fresh cold water. Bring to a boil very gently indeed and allow to boil for 2 minutes, no more. Drain and plunge them into cold water in a bowl under a running tap, leaving them until they are cool and firm to handle.
Remove from the water and trim off the gristly bits, but leave the thin membrane on or they may disintegrate in the cooking. Wrap each sweetbread in a piece of wax paper. Place on a board and set another board on top with a weight to procure an even thickness. Leave under the weighted board for at least 2 hours, or in the refrigerator until you want them.
Discard the paper and wrap each sweetbread in a slice of fatback or bacon. Secure with thick string. Using an oven dish that will receive the sweetbreads snugly, scatter the carrots and shallots over the bottom with a few parsley sprigs. Put the sweetbreads on top and pour in the white wine. Set the dish over the heat and cook until the wine begins to bubble. Add enough stock or water to cover the contents, and season to taste. Bring to simmering point, then cover and place in a
Meanwhile, fry the mushrooms, including the stalks, in half of the butter until the juices run.
Remove the sweetbreads from the oven and untie the string. Very gently saute them in a pan in the remaining butter until they are the palest gold on each side. Add the mushrooms and 2 tablespoons of the sweetbread cooking liquid. Pour in the cream, turn up the heat, and jiggle the pan until the cream thickens. If necessary, add a little more of the cooking liquid to thin the sauce.
Place the sweetbreads on a warmed serving dish. Give the sauce another twirl, season to taste with salt and pepper, and pour around the sweetbreads. Serve with croûtons of French bread fried in butter or, alternatively, place the croûtons under the sweetbreads.
© 1999 Jennifer Paterson and Clarissa Dickson Wright estate. All rights reserved.