As a non-closeted internet addict, I spend an inordinate amount of time on Reddit, where I occasionally like to post a food photo or two just to get a quick gauge of how popular a recipe might be on Serious Eats. If Reddit's 1,718 upvote response to smashed potatoes fried in duck fat is any indication, my family (and hopefully yours) is gonna enjoy eating these pretty immensely on Thanksgiving.
For years, I've been serving Ultra-Crispy Roast Potatoes for all major holidays using a technique I first read about in The River Cottage Cookbook. The idea is simple: boil chunks of potatoes in salted water until they are tender, toss them in a large bowl with some fat using a fork to bash and roughen-up their surfaces, then roast until crisp. The par-cooking and bashing steps are key, as they add surface area to the potato chunks, allowing them to roast up with a thick, ultra-crisp shell. They're crunchier than the best french fry, and packed with great roasted flavor.
Indeed, the only potatoes I've had better are the ones that April Bloomfield serves at the Spotted Pig as a side dish to her roast suckling pig. For those potatoes, she utilizes the same concept—par-boiling and roughing-up—but instead of roasting, follows it up with a deep-fry in duck fat. The results are gloriously golden brown, crisp nuggets with fluffy, potato-y centers. The crisp nooks and crannies around the edges capture that wonderful duck aroma, giving them an almost meaty bite. There are few things in the world that go better together than potatoes and duck fat.
The one issue with April's recipe is that the potatoes say in large, irregular chunks that require a ton of fat in a deep pot to deep-fry properly. To get around that problem, I took a cue from my Colombian wife and her native country's patacónes; crispy plantain disks that are that are par-cooked, smashed flat, then fried again. You'll see them as tostones in other parts of Central and South America.
Rather than starting with chunks or larger potatoes, I use whole new potatoes boiled until soft (any variety will do, though red-skinned varieties will end up more creamy in the center, while yellow or white-skinned varieties will end up fluffier). After smashing them under a frying pan, the skins burst and the flesh spreads around, giving the finished disks some awesomely frayed edges for crisping.
Once flattened like this, they can be fried off in a shallow layer of duck fat (or fine, vegetable oil if you'd like). The key is a slow, gently fry, which gives plenty of time for excess moisture to leave the outer layer of the potatoes, leaving behind an extra-thick crisp crust around them
Pan-frying does limit the number of potatoes you can cook at a time, but the good news is that you can cook them in advance—even refrigerate them overnight—then re-crisp them in a hot oven just before serving. They'll end up just as crisp-on-the-outside creamy-in-the-middle as fresh-fried. It makes last minute prep before the big meal a snap.
Make far more than you think you'll need because these will being disappearing from the kitchen long before you even get them to the table.