A great alternative to potato gratin (and all of the carbs that goes along with it). I usually make my gratin with potatoes but having a diabetic father-in-law requires a little tweeking of some of my recipes. This recipe is a great lower carb alternative and is still quite decadent! I topped it off with a little bit of the Black Sheep Creamery cheese that was included in the most recent farm share but can be swapped out with an aged manchego or romano cheese. The caramelizing of the leeks and shallots add a wonderful depth of flavor to the dish. Enjoy!