2 Days before eating, cover sweetbreads with milk and refrigerate overnight. Discard milk, rinse and remove any veins
1 Day before eating, place sweetbreads in pot and cover with water, add big pinch of salt and 1 T lemon juice. Bring water to a boil and blanch for 5 min. Plunge into ice bath.
Wrap sweetbreads loosely in towel in a single layer. Place heavy weight on top and refrigerate overnight.
Slice into medallions, dredge in flour seasoned with salt and paper.
Melt butter in skillet and cook sweetbreads over medium heat until brown. Drain on paper towels
Whisk 1 T lemon juice, olive oil, salt and pepper until emulsified. Add celery and parsley, mix. Drizzle on sweetbreads and serve.