Potatoes au gratin's soft layers of creamy potatoes topped with a golden, slightly crispy crust, embodies the definition of comfort food, especially with a couple layers of bacon nestled in between the potatoes. The dish isn't complicated, but it does benefit from attention to detail and quality ingredients. One key to the preparation of this recipe: While baking, break the crust the cream forms a few times. This allows the cream and potatoes to slowly cook into one another, perfectly softening the layers of potato, while preventing the top layer from overcooking. After the third break, you should notice a difference in consistency of the cream and it will appear slightly more translucent, almost as if the cream was combined with melted butter.
Prep tip: It helps to take a slice or two off the bottom of the potatoes before slicing the rest of it. It gives the potato a flat surface to lay on as you slice.
Preheat oven to 350 degrees F.
Heat a saute pan over medium heat. Cook bacon until very lightly golden on each side. Remove from pan and drain on paper towels. Set aside.
Slightly crush garlic cloves to open it up. Rub garlic over inside of 9-by-13-inch baking dish.
Put sliced potatoes in a large bowl. Toss with thyme, salt and pepper until evenly coated. Layer 1/3 of potatoes in bottom of baking dish. Cover with a single layer of bacon. Layer another 1/3 of potatoes, another layer of bacon, then final layer of potatoes. Pour cream over potatoes. (Should be enough cream than when potatoes are pressed down on, cream rises above potatoes.) Place dish on sheet pan and put in oven. Bake for 30 minutes, pull out of oven and with the back of a large wooden spoon, break the crust the cream is starting to form. Return to oven. Bake for another 20 minutes and repeat crust breaking. Bake for another 20 minutes, then break the crust again. After third crust break, return to oven and continue to bake for another 20 minutes or until top is golden brown.
It is best to allow it to cool for about 15 minutes before serving, since it will be very hot coming out of the oven and will hold its heat quite well.