- Rinse the sweetbreads under cold running water for 5 minutes. Place them in a large bowl of water and let them soak in the refrigerator for 24 hours, taking care to change the water several times during the process.
To prepare the broth
- Place all the ingredients in a large pot and bring to a boil. Simmer for 20 to 30 minutes to get a good aroma. Strain the broth and pour it back into the pot. Heat to keep the liquid at a simmer.
- Blanch the sweetbreads in the simmering broth for 7 minute. Meanwhile, prepare a bowl of ice water. With a slotted spoon, remove the sweetbreads and let cool for 5 minutes in the ice water to stop the cooking process.
- With your hands, remove the thin white membrane covering the sweetbreads. (This operation must be performed quickly but gently.)
- Place the sweetbreads between two plates and refrigerate for 1 hour to remove any excess water.
To prepare the butter
- Blanch the parsley for 3 minutes in a pot of boiling water. Meanwhile, prepare a bowl of ice water. Transfer the parsley to the ice water to cool it. Drain the parsley, squeezing with your hands. In a food processor, purée the parsley and the very cold water. Proceed quickly to avoid overheating the purée (otherwise the sauce will lose its beautiful bright colour). Strain through a sieve place over a bowl. Collect 1/2 cup (125 ml) of this green juice for the recipe. Keep in the refrigerator.
- With a peeler, remove long strips of the cucumber and place in a colander. Sprinkle with 1 tbsp of the fine salt. Toss and let drain for 30 to 45 minutes. Rinse under cold running water and let drain in the colander until ready to cook the cucumber.
Just before serving
- Cover the bottom of a skillet with grape seed oil and heat until the oil is hot.
- Meanwhile, season the sweetbreads and dredge quickly into flour. Shake to remove any excess. Place in the hot skillet and brown for about 1 1/2 minutes on each side. Reduce the heat by half. Add 1 tbsp of the butter and keep it to a frothy stage, lowering the heat even more, if needed. Continue cooking for 5 minutes.
- Transfer the sweetbreads to a warm plate. Wipe the skillet clean and heat 1 tbsp of the butter. Sauté the cucumber ribbons for 2 minutes. Drizzle with a few drops of lemon juice and remove from the heat.
- Heat the parsley juice in a small saucepan, taking care never to bring to a boil. Whisk in the diced butter. Remove immediately from the heat and season with salt (you must avoid boiling. The juice would change colour and lose its emulsion). Adjust the seasoning.
- Coat the bottom the serving plates with the parsley butter, add the warm cucumber ribbons on the parsley butter and top with the sweetbreads.
This recipe is published in Stelio Perombelon’s book "25 verbes pour apprendre à cuisiner".