Step 1: Thinly slice the onions. Place the onions in a bowl with the vinegar, bay leaves, and salt. Stir to mix and allow them to sit for 4 hours.
Step 2: Stir in the sugar and allow the onions to sit for another 5 hours. Pour the onions in a pot and allow them to cook over low heat for 40 minutes.
Step 3: Place the red onions in jars and store them in the fridge.
