Potato Onion Gratin (without cream)

Gratin refers to the cooking vessel as well as the method of cooking, and the dish itself. So, slipping some vegetables into a gratin dish, cooking them in the oven so the top gets browned and crisp (gratinéed), yields a gratin. I do lots of them in the summer with things like tomato, eggplant, summer squash, and onions, but I love a potato gratin year-round. When it is warmer, I prefer to make them just with stock rather than using dairy such as cream, and I skip the cheese unless I grate some on in the last few minutes. This recipe gives an option for this.

INGREDIENTS:

2 cups onions, sliced ¼ inch

8 medium Desiree (or other) potatoes, ends removed and sliced 1/8^th thick

2 cloves garlic, minced, plus one for seasoning the baking dish

1 tablespoon minced thyme

½ cup white wine

2 cups vegetable stock, hot

salt and pepper to taste

Olive oil as needed

-OPTIONAL-

1 cup grated cheese such as Gruyere, Jarlesberg, or a mix of Parmesan and Romano

METHOD:

Heat the oven to 400°F.

Rub a  2 quart (7 inch by 11 inch Pyrex casserole), or an equivalent dish, with the garlic clove (or use one destined to be minced) hard enough to leave traces of oil on the dish.

Heat a sauté pan over medium-high heat. When hot, add enough oil to film the bottom of the pan. When the oil is hot (the surface of the oil will shimmer), add the onions. Cook until the onions are well wilted and just starting to color. Add the a teaspoon of the thyme and toss to combine. When fragrant, add the garlic, and toss to combine. Cook until the garlic is no longer raw, then add the white wine and cook down until the wine has evaporated.

Transfer 1/3^rd of the onions to the bottom of the gratin dish and spread out. Put the rest of the onions in a bowl large enough to hold them and the potatoes. Add the potatoes, reserving a couple handfuls, to the bowl and mix with the onions, the rest of the thyme, and if you are using it-the cheese. Season with salt and pepper, tossing again to mix well, and pour into the gratin dish atop the onions.

Using the palm of your hand, push down on the potatoes to level and compress them. Then, starting at one end and using the reserved potatoes, place them across the width of the pan, trimming the ends off if needed to get them to fit well against the edge of the dish. Scale on the next row of potato slices, over-lapping 3/4s of the slice already down. Continue all the way across the surface of the gratin, again trimming the ends for a flush fit with the other end.

Pour in the hot stock so it comes three-quarters of the way up the side of the potatoes or a little more. If you did not have enough stock, supplement with water.

Season the top with salt and pepper and place in the center of the oven.

Cook for 1 hour or until it the gratin is done. The surface should be golden with a few darker spots and crisping on edges. The potatoes should be tender-easily pierced by a knife tip-and the liquid should be absorbed. If there is still a lot of liquid, cook the gratin a little longer of you think it will not burn. Otherwise, use a rolled up paper towel slipped into a corner to wick away extra liquid.

If you wish to, you can scatter cheese over the surface of the gratin in the last ten minutes of cooking to prevent burning and to give a nice look to the top.

Remove from the heat and let the gratin cool a little so it sets up. Serve warm.

Chef’s Notes and Tips:

If you wish, you can lay in all the onions in the bottom of the dish and then add the potatoes. You can also scale in all the potatoes slices, using a 3:1 scale for this (3 potatoes scaled over each other for the length of one slice.) You could alternate, from bottom up, onions, a layer of potatoes, a layer of onions or onions and cheese,  and potatoes to finish.

Serves: 4

Source: Chef Andrew E Cohen