2 onions, 2 leeks, 6 celery stalks, 1 bay leaf, juice of 1 lemon, 12 large lambs’ sweetbreads, 200g pearl barley, rinsed, 1 bunch of thyme, tied with string, 300 ml olive oil, 1 bunch of flat-leaf parsley, leaves picked, 1 bunch of mint, leaves picked, 2 round shallots, peeled and sliced, 1 teaspoon of capers, approximately ¼ volume of olive oil to lemon juice used, 1 garlic clove, finely chopped, oil and butter for frying, splash of sherry vinegar, salt and freshly ground black pepper.
Fill a large pan with cold, salted water. Slice 1 onion, 1 leek and 3 stalks of celery, and add to the pan with the bay leaf. Bring to the boil, squeeze in the juice of half the lemon, and blanch the sweetbreads for 4-5 minutes until firm. Remove the sweetbreads and peel off the fat and membrane while still warm, season with salt and pepper and set aside. Discard the stock.
Put the pearl barley in a pan with 750 ml of water, the remaining onion, leek and celery, roughly chopped in large pieces so you can remove them easily at the end of the cooking time. Add the bunch of thyme and cook until the pearl barley is tender, following the packet instructions.
Drain, discard the vegetables and thume, and dress the pearl barley in a little olive oil. Leave to cool, then toast briefly on a large flat baking tray in a preheated oven, 180 degrees C for 20 minutes.
Roughly chop the parsley and mint leaves and place in a mixing bowl with the shallots, capers and pearl barley, and keep warm.
Make a dressing by mixing together the olive oil, remaining lemon juice and garlic.
Heat a large frying pan over a high heat, then reduce the heat to medium and quickly fry the seasoned sweetbreads in oil and butter until golden brown all over but still moist inside. Add a splash of sherry vinegar to the pan, briefly deglaze (by scraping and dissolving any deposits in the pan with a wooden spoon), stir, then take off the heat. Add the hot sweetbreads to the pearl barley mixture, dress with the olive oil and lemon dressing and taste for seasoning before serving.