Make the marinade: Pour the cooking wine into a large bowl. Add the garlic, red onion, oregano, 1 tbsp mint, bay leaf, salt and cloves to the wine. Stir to combine well.
Pat the lamb meat dry, then put it in a large plastic storage bag. Pour the marinate into the bag and seal. Gently toss the marinade with the meat to get the meat well-coated. Open the seal a bit and press out excess air, then seal the bag and put in the refrigerator. Marinade the meat for at least 8 hours, preferably overnight.
Start making the stew by pre-heating oven to 325.
Heat 1 tbsp olive oil in a dutch oven. Add the yellow onion, and sauté for a few minutes. Stir in the parsnip, carrot and bell pepper, and cook for about 5 minutes.
As the vegetables begin to cook, get the lamb ready. Set a bowl underneath a strainer, then pour the lamb and marinade into the strainer. Set the marinade from the lamb aside to be used shortly.
Scrape the bits of garlic, herbs and other ingredients off the lamb, saving the garlic and oregano for use in the stew. Pat the lamb dry, then add it to the dutch oven with the vegetables.
Turn the heat to medium high, add salt and pepper to taste, and brown the lamb meat. Stir occasionally to get it browned on all sides, which will take 5 to 1o minutes.
Stir in the 2 cups reserved marinade and stock. If you have less than 2 cups marinade left, add additional stock so that you have a total of 2 1/2 cups marinade plus stock.
Stir the tomatoes, tomato paste and a tablespoon of mint into the dutch oven to combine with the lamb. Coarsely chop the garlic and oregano reserved from the marinade, then stir that into the stew along with the leek top if you are using it.
Bring the liquid to a boil, then reduce to a simmer. Give it a good stir, then add the cover. Carefully transfer the Dutch oven to the oven.
Cook for one hour at 325. Lower heat to 300, and braise for 2 more hours at 300.
After 3 hours of cooking time from the oven, carefully remove the stew from the oven and place on the stove top. Remove the cover, and stir in a tbsp of mint, the chopped olives and lemon juice.
Serve the stew in shallow bowls over couscous or rice pilaf. Pass feta cheese at the table and people can top with the amount of feta they would like. Enjoy with a glass of Greek red wine!