Heat 1 tbsp oil in a casserole dish over a high heat. Fry the lamb in two batches for 5 mins each until evenly browned. Remove from the pan and set aside.

Heat the remaining oil in the same pan and fry the onion and leeks over a medium heat for 7 mins. Tip in the carrots and two-thirds of the garlic, then fry for 1 min. Stir the meat into the pan along with the plain flour and fry for another 2 mins. Add the thyme and bay leaf, then the wine and bring to a bubble before pouring in the stock. Mix everything together well. Put a lid on the pan and cook over a low heat for 2 1/2-3 hrs or until the meat is tender. Add the buckwheat for the last 20 mins of cooking time.

Mix the remaining garlic with the lemon zest and parsley. Serve the stew in bowls, scattered with the parsley and lemon mixture.