Prepare the Soup

• Prepare the leeks by cutting off the green tops and the tip of the root end. You will only be using about 4-5 inches of the white and light green part of the leek. The root end can be discarded, and the green tops can be used for vegetable stock if desired, otherwise discard.
• Fill a large bowl with cold water and set aside. Slice the part of the leeks you will use lengthwise and rinse them under water to remove some excess sand, then place them in the bowl of water. Rinse the leeks in the water bath and change the water 2-3 times to remove all the sand and dirt from them. Remove the leeks from the water and slice them thinly (about ⅛-1/4 inch thick). Set aside.
• Meanwhile, heat a large pot or Dutch oven for your soup over medium heat and add your olive oil. When the oil is hot, add the pancetta and cook until the fat has rendered. Next, add the butter, and when melted, turn the heat to medium-high and add the leeks, salt, and pepper. Stirring often, cook until the leeks start to caramelize. Some will not be caramelized at all, and some will be a deep brown, with most in between showing some golden brown color.
• Next add the garlic to the caramelized leeks and stir for 30 seconds. Then, add the potatoes and stir. Using a wooden spoon, add about ½ cup of the stock and scrape the bottom of the pot to deglaze, if necessary. Add the rest of the stock and bring to a boil. Reduce the heat to low and simmer for about 30 minutes. After 30 minutes, test the potatoes to ensure they have no resistance to a skewer or fork.
• At this point, you can use an immersion blender or a countertop blender to purée the soup. If using the immersion blender, just ensure you blend it enough to become as smooth as you want it to be. If using a countertop blender, be extremely careful to start the blending process on the lowest setting and gradually increase the speed until blended. Hot ingredients will explode in a blender if started on too high of a setting.
• In the large soup pot with the puree, add the cream, milk and rosemary and stir to incorporate. Bring to a boil, then reduce the heat to low and simmer for another 30 minutes, stirring occasionally. Taste for seasoning and season soup with more kosher salt if needed.
• If desired, serve with the parsley, chile oil, and/or cracked black pepper on top, along with crusty bread or garlic toast!