Method

• Trim the dark green & roots of the leeks. Slice leeks (I used mandolin). 
• Rinse thoroughly to remove any grit and drain well.
• Heat oil in a large pan over medium low heat. Add the leeks and salt. Cook gently for 5-7 minutes with lid on, stirring occasionally until they soften and release moisture.
• Stir in brown sugar, butter, balsamic vinegar and water. Bring to a gentle simmer. 
• Reduce the heat to low and simmer uncovered, stirring occasionally for 30-40 minutes, or until leeks are very soft and most of liquid has reduced to a thick glossy glaze. Season with ground black pepper and seasoning to taste.
• You can add more balsamic or sugar depending on your flavour preference. If it seems to wet towards the end, increase heat slightly and stir more often to reduce the liquid.
• Enjoy with bread and blue cheese!