Heat 2 tablespoons of oil in a casserole and brown the roast on all sides. Slice the roast into 1 cm slices, with an electric knife if possible, without going to the end.
Arrange a slice of cheese and bacon between each slice of meat.
Put the roast back together by wrapping it around the bard, tie with kitchen string. Place in an ovenproof dish, surround with garlic cloves and bay leaves. Drizzle with 2 tablespoons of olive oil and bake for 30 minutes in a preheated oven at 200 °C, basting regularly.
Peel the carrots and celeriac. Cut the carrots into cubes and, using a melon baller, cut the celery into balls.
Boil a large quantity of salt water and plunge the crosnes into it, 5 minutes. Drain and rinse and set aside
Melt 40 g of butter in a casserole dish and add the carrots and celery. Season with salt and pepper and cook over high heat for 2 minutes, then lower the heat and continue cooking for 5 minutes. At the end of the veal's cooking, arrange the vegetables in the dish and sprinkle with 2 tablespoons of olive oil. Return to the oven for 10 minutes. Season with pepper and eat hot.