Remove the blood vessels from the sweetbreads. Soak it in cold
water for 2 hours. Drain well and cut it into small pieces.
Put the sweetbreads to the cooker, cover it with cold water and
bring to boil for 3 minutes. Drain and rinse with cold water.
Heat the oil in the cooker. Put the bacon, onion and celery and
fry them until softened. Lift them out from the cooker and drain
well.
Put the sweetbreads to the hot oil and fry until lightly
colored.
Put the vegetables and bacon back to the cooker, add the stock,
bouquet garni, salt and pepper. Stir well.
Close the cooker and bring to high pressure then cook for 6
minutes.
Reduce the pressure immediately.
Drain the cooking liquid off, strain and reserve. Put the
sweetbreads to a warm serving dish. Keep it hot.
Place the cooker back to heat then add the margarine and wait
until it gets melted. Stir in the the flour and cook for 1 minute.
Remove the cooker from the heat and stir in the reserved milk
and cooking liquid. Place the cooker back to heat, bring to boil and
stir. Add 50 grams of cheese and season with pepper and salt.
Put the sauce over the sweetbreads and sprinkle the remaining
cheese on top. Place it over a hot grill and brown on both sides
then serve.
