Preparation

1. Trim leeks to remove root ends, tough or damaged outer layers, and dark green top parts; reserve trimmings for stock if desired. Cut leeks in half lengthwise, then rinse each leek half under cold, running water, gently fanning layers open while being careful to keep leek halves intact, to wash away any sand or grit. Pat dry.
2. Preheat oven to 350 degrees and adjust rack to middle position. Heat oil in a 12 inch heavy bottomed skillet over medium-high heat until shimmering. Working in 2 batches, add as many leeks as you can fit in a single layer cut side down. Cook until well browned, about 3 minutes. Transfer leeks to a 9 X 13 inch baking dish, arranging them in a single layer, cut side up. Repeat with any remaining leeks until all leeks are browned.
3. Pour wine and chicken broth into the skillet; bring to a simmer. Sprinkle leeks all over with salt and pepper, dot with butter, and then pour the hot wine and broth mixture on top. Cover tightly with aluminum foil and bake for 30 minutes. Remove foil and continue to cook until leeks are completely translucent, about 20 to 30 more minutes longer, depending on thickness of leeks. Remove from oven and sprinkle with cheese. Let sit 5 minutes.
4. Transfer leeks to a serving platter. Transfer pan juices to a small bowl and stir in lemon zest and lemon juice and season with salt and pepper, if desired. Pour braising sauce over leeks and sprinkle with chopped parsley.