In a medium dutch oven, sautee the leeks in butter for 2-4 minutes over medium heat. Add the carrots and celery and cook for 3-5 more minutes. Add potatoes and flour and cook for 3 minutes. Add the 4 cups of stock and bring to a boil for 5 minutes. Cover your pot (make sure to tip the lid so it doesn’t simmer oveand simmer for 30 minutes stirring occasionally. After 30 minutes (make sure potatoes are nice and soft), add the half and half, parsley and salt and pepper to taste and simmer for an additional 15 minutes. Top with Kayem bacon right before serving.