• In a heavy roasting pan, sear the ossobuco pieces on both sides in a little olive oil and set aside.
• Then finely chop the onion in the roasting pan and sauté 280g of it in olive oil; keep the remaining 20g for the vinaigrette.
• Add the ossobuco slices to the onions. Add the tomato purée and pour in the white wine and veal stock. Add the herbs and peppercorns in a spice bag. Simmer for at least 4 hours. Season to taste with salt.
• In the meantime, peel and finely chop the carrot. Finely peel the outside of the celeriac with a peeler and then finely chop. Mix the chopped carrots, celery and the remaining 20g finely chopped onions with the lemon juice and lemon zest to make a "vegetable vinaigrette".
• Arrange the cooked ossobuco slices on a large platter together with the braising sauce. Finish with the vegetable vinaigrette and chopped parsley.

The ideal accompaniment to ossobuco is a risotto Milanese with saffron.