• Finely chop the peeled celery root and garlic. Cut the onion in half without peeling. Cut the leek into rings. Peel the carrots and chop with a shaped knife into pucks.
• Heat a frying pan with olive oil and fry the shanks on both sides until browned.

Option 1: Osso buco in the slow cooker (perfect for busy days)

• Roast the vegetables in a frying pan and transfer them to the bowl of the slow cooker. Add the tomato slices and tomato paste.
• Pour in the wine and broth. Add the shanks, bay leaf, salt and pepper to taste. Cook on low for 6-8 hours or on high for 4 hours.

Option 2: Osso buco in the oven (classic way)

• Preheat the oven to 160°C (320°F). In a ceramic pot, roast the prepared vegetables until transparent. Slice the tomatoes and place them in the pot. Continue cooking for a couple more minutes.
• Pour in the stock and wine. Place the roasted shanks. Add the tomato paste, salt and pepper. Cook in the oven for 21/2 to 3 hours. At the end of cooking, add bay leaf and turn off oven. Leave the pot in the oven for 10 minutes.

Option 3: Osso buco on the stovetop (quick version)

• 3- Roast the vegetables in a saucepan. Add the tomatoes, stock, wine and tomato paste. Salt and pepper the dish.
• Bring to a boil and cover with a lid. Reduce heat to low and cook the osso buco for 2-2 ½ hours. Ten minutes before the end of cooking time, add the bay leaves. Turn off the heat and leave the dish on the stove to infuse. Remove the bay leaves.
• Transfer the shanks to a serving dish along with the vegetables and gravy.