Clean and cut the leeks into small slices.Fill a pot with water and a pinch of salt. Bring to a boil. Prepare a bowl of ice water. Blanch the leeks for 30 seconds. Transfer them to the ice bath. Drain, let dry, and put into a Mason jar.
Heat some water, vinegar, salt, sugar, and other spices in a saucepan until the sugar dissolves.
Pour the mixture into the jar, wait for it to cool, then close the lid. Store in the fridge.