Gratin Dauphinois | TASTE

Preheat your oven to 375°F. Peel potatoes and slice on a mandoline to 4.5mm or 3/16 of an inch, just a little thicker than the width of a nickel using a knife. Heat a tablespoon of butter in an enameled Dutch oven or other medium-size ovenproof pot, just until it melts. Swirl it around the base and sides to coat. Scatter half of the garlic and thyme (if using) in the bottom of the pot before layering all the potatoes, overlapping slices on each other by a third so that they are evenly shingled. Sprinkle each layer with salt, pepper, and a light grating of nutmeg. Top with the remaining garlic and thyme, and pour the half-and-half in against the side of the pot so as to not disrupt the layers. Move the pot to the stove, and bring the potatoes to a gentle boil over medium. Once the half-and-half starts to bubble, dab the remaining butter over the top, and move the gratin to the oven. Check on the tenderness after 45 minutes by inserting a thin knife through the middle-there should be absolutely no resistance. Let cool for at least 10 minutes before serving.