This is one of my favorite fall recipes because it is just perfect with a roast or paired with lamb chops. For a more robust dish, use the maximum amount of gruyere. Butter is optional but not the the vermouth which adds nice depth of flavor. It is important that the potatoes be close to uniform in size so that they all cook evenly (and most importantly, don't get too soft). The end result should be tender potatoes steeped in a rich flavorful cream sauce. Finally, ENJOY! —AlexisC
Test Kitchen Notes
The secret to a great gratin is not trying too hard. Potatoes are delicious; there’s no need to smother them. And this is a point that AlexisC clearly gets. Her potatoes are gently scented with leek and garlic and enriched with cream and Gruyere. AlexisC has you bake the gratin at a fairly low temp – 300 degrees – so by the time the gratin emerges from the oven, the layers of potato are buttery in texture and topped with a crisp, caramelized crust. As for all gratins, buy yourself a mandoline (the best are the inexpensive Japanese-style ones) – it will preserve your sanity and make for uniform slices. - A&M —The Editors
4 to 6
Leeks (medium size)
Vermouth (or dry white wine)
2 to 2 1/2 pounds
Boiling Potatoes (approx 6-7medium size potatoes such as Yukon Gold)
Remove roots and green leaves from leeks. Wash and dry the white part of the leek.
Split leeks in half lengthwise. Then chop crosswise into thin to medium size half moon crescents. Dice garlic
Sauté leeks slowly in approximately one tablespoon of the butter on medium low heat in a nonstick pan until soft but not brown (about 6-8 minutes). Add garlic and sauté for a minute more. Add a dash of vermouth (or white wine) and sauté a minute more until most of the vermouth (white wine) has evaporated. The leeks should be damp, but not swimming in vermouth (white wine). Remove leeks from heat, cover and let sit.
Peel and slice potatoes evenly into approximatly 1/8 inch slices. Dump slices in cold water as you slice so that the potatoes don’t turn brown. (note: I peel and slice each potato individually rather than peeling them all first so that the peeled potatoes spend less time sitting around possibly turning brown.)
Grate a block of gruyere so that you have 1 cup of grated gruyere.
Lightly butter the baking dish. Drain potatoes taking care not to break them.
Lay down one layer of potato in the dish. Sprinkle generously with salt and pepper. Then sprinkle with sautéed leek mixture. Then sprinkle with some of the gruyere. Finally dot with one or two bits of butter (optional). Repeat sequence until all potatoes are used. The last layer should be just a layer of potatoes.
Slowly pour cream all over potatoes in dish. Finish with a few shavings of gruyere which will give a nice color and a little bit of crust. Bake for approximately 1 ¼ to 1 1/2 hours. Cream should simmer and may even gently bubble, but it should never boil (boiling will cause the cream to separate and curdle). It’s done when it has a nice golden brown / orange color; the potatoes are tender but still hold their shape; and the cream has thickened and reduced slightly. Let cool for 15-20 min before serving.