• Preheat the oven to 150C.
• Place the onion, carrot, celery, garlic and rosemary in a processor and process until finely minced. Alternatively, chop everything into small dice using a sharp knife.
• Season the lamb shanks with salt and pepper.
• Heat a heavy-based ovenproof casserole over medium heat and when hot add some olive oil. Add the lamb shanks and brown for a few minutes on each side. Remove from the pan and set aside. 
• Add the chopped vegetable mixture to the pan, add more olive oil as needed, and sautè for 10 minutes to soften. Next, add the tomato paste and cook for a minute or two. Then add the porcini powder (if using), bay leaf, orange peel, tomatoes, stock, vinegar & sugar and bring to a simmer. Return the lamb to the pan, cover with a lid and place in the oven. Cook for 2 to 2 1/2 hours or until meat is tender and pulls away easily from the bone. Remove the lamb from the pan and set it aside. When the meat is cool enough to handle shred the meat using two forks.
• Place the casserole back on the stove and simmer the sauce for 10-15 minutes or until it has reduced and thickened. Return the lamb to the sauce.
• Serve with a ribbon pasta such as pappardelle or tagliatelle, or with soft polenta, and add a dollop of mint and pea pesto. Buon appetito!

Pea & mint pesto

• Place the peas, mint, garlic, pinenuts, parmesan, lemon zest and salt & pepper to taste in a food processor and pulse to combine.
• With the motor running slowly add the olive oil until desired consistency is achieved. Taste & adjust seasoning. The pesto may even benefit from a squeeze of lemon juice, so add that if you feel it needs a lift!