Last week, I found myself coining a new handle for a pasta dish. And today I can't figure out the name of my new second-favorite potato preparation (after french fries). I believe it has one: The idea doesn't originate with me, though I worked out the actual procedure myself because there was no quick way to look it up without knowing what it was called or remembering where I'd run into it.
Still, it's a fine thing to serve next to almost anything that has an affinity with potatoes: it has a little of the richness and softness of gratin (scalloped) potatoes, a little of the pure flavor of baked and a lot of the crusty crunch of roasted or fried. It takes forethought but not much by way of technical skill or ingredients. It is also a thing of beauty.
Here's how I made eight side-dish portions of it, whatever it is: A day ahead (it could have been half a day or several days), I set the oven to 350 degrees F (175 C) and buttered a small (roughly 6 inches long by 3-1/2 wide x 2-1/2 deep, or 15 x 9 x 6 cm) loaf-shaped pan and lined it with strips of parchment paper, also buttered (see photo). I peeled and washed three largeish russet (Idaho) potatoes (whatever variety you use, let it be starchy), then sliced them about 1/8 inch (3 mm) thick on a mandoline; a knife would have worked just as well but not as fast. Without rinsing the slices (their starch helps hold the dish together), I put them into a bowl with salt (lots), pepper (a little) and around 2 tablespoons of melted butter, and stirred/tossed to get seasoning and fat onto each slice, however unevenly.
I then layered the potato slices into the mold, sometimes neatly, sometimes not, but always trying to avoid gaps by pressing with my fingers and using half-slices where necessary. Two or three times, I paused and sparingly drizzled the potatoes with cream; I used a mixture of crème fraîche and heavy cream, but heavy cream alone is fine - it was just that I wanted to use up the last of a container of crème fraîche. The three good-sized potatoes over-filled the mold, which was the idea; I gave them a final press with my hands, then folded the parchment paper over the top, laid a sheet of waxed paper over this, then a double layer of aluminum foil. Why the waxed paper? Because my mold was stainless steel, which could have reacted with the food and the aluminum, potentially generating off-flavors and burning weird holes in the foil.
This went into the oven on a tray (to catch spills, which never materialized) for an hour; I poked through the foil and paper with a slim skewer to find that the potatoes were not thoroughly cooked: they must present no notable resistance to the probe. After another 20 minutes, they were properly tender.
At that point they came out of the oven, the foil was peeled away and a similar pan was used as a piston to compress the potatoes; I applied moderate force, because too much would crush the potatoes. Then I weighted that second pan with a can of tomatoes and left the setup to cool to room temperature before being put in the fridge overnight. The next day, I ran a knife between the mold and the paper lining to free the sides, inverted the mold and applied a cloth soaked in hot water to what had been the bottom, which softened the butter and released the potatoes in loaf form. The loaf I encased in plastic wrap and returned to the fridge until dinner time.
While the main course - a big ol' rib steak - was resting, I evened up the edges and cut the loaf into eight slices and browned them on both sides in a non-stick skillet, with olive oil; over medium-low to medium heat, this took about five minutes per side. The goal is a crisp, brown crust and an interior that is thoroughly hot. If a few bits of potato come away from a slice as you're turning them, just push them back into place, though with any luck this won't happen.
There are lots of ways in which this could be fancied up, but a little butter, a little cream and plenty of salt are all that any potato really needs. And this dish is about the potato in both its crisp and its tender forms.
Update on nomenclature: I just read a review of the London restaurant Portland, which does a similar potato dish, but made with thinner-cut potatoes and deep fried. They call it a millefeuille, which has a certain tempting ring to it. And the excellent chef Neil Borthwick has offered something along the same lines at his restaurant Merchants Tavern, also in London; he called it potatoes sarladaise, because he employed duck fat rather than butter and the south-western French town of Sarlat is Duck City. Which is a pretty nifty idea.
