Cut leeks in half lengthwise and place in bowl of cold water to remove sand. Rinse under cold water and pat dry.
Pre-heat oven to 400 F. Lightly grease a large baking sheet or dish.
Place leeks on prepared baking sheet. Drizzle with olive oil and sprinkle with salt and pepper. Roast leeks until they are tender, about 35 to 45 minutes. While roasting, drizzle leeks with broth and water mixture a few times to keep moist.