This side dish is made based on Julia Child's Potato Dauphinois Gratin but has a twist of the addition of sautéed leeks and resembles in taste the famous Potato Leek Soup; This casserole is full of flavor with garlic, cream, Gruyere cheese, and thyme. It's rich, decadent and elegant at the same time. It can be served as a perfect side dish for any Holidays or other gatherings.
1. I used yellow potatoes, but Russet will work great as you need starchy potatoes
2. If you cannot find Gruyere or you don't want to use it as it is pretty pricey, you may substitute with Cheddar or other well-melting cheese.