“What if we cooked potatoes like meat?”
That’s the basic premise of pommes de terre fondantes, or melting potatoes, another classic of French spud cookery that combines elements of traditional French braising and butter-basting techniques. Unlike laborious and finicky dishes like pommes Anna or dauphine, fondant potatoes are remarkably simple to make: Sear potatoes in fat until well-browned, then simmer them with stock, aromatics, and plenty of butter until they’re creamy and spoon-tender. That’s it. It’s the kind of side dish that you can actually pull off without much fuss on a weeknight, but it’s also worthy of a holiday or special occasion.
Start by peeling and trimming the ends off of small Yukon Golds—their firm, waxy flesh is ideal for braising and roasting—before halving them crosswise to produce pieces with two flat sides that are well-suited for searing. Because we want to brown the potatoes before braising them, it’s important to dry them thoroughly and start them in a hot skillet with plenty of fat. Any neutral oil will work for this step, but if you have any rendered animal fat kicking around, this is a great opportunity to use it. Duck fat, schmaltz, and beef fat are all great options that’ll lend rich depth of flavor to the potatoes—just avoid whole butter because the sugars and milk solids will burn before the potatoes have time to brown. If you don’t have fat already rendered, but plan on serving this side with something like a steak or a roast; you can render trimmings or do an initial sear on the roast’s fat cap and produce enough fat for browning the potatoes, get them in the oven, and then turn your attention back to the meat.
Searing the potato pieces is a lot like the technique for searing scallops: sear them broad side down without moving them until they begin to brown around the edges and release from the pan when you swirl the skillet, then, when they’re a deep golden brown, flip them over and add a generous amount of butter. This produces a great sear on the first side, and then starts the process of building the braising sauce. Thyme and crushed garlic cloves go in next to infuse the butter, for a butter-basted steak vibe. But unlike something like French brown butter potatoes, it’s not all about cooking in fat for pommes fondantes. We need to add stock in order to get them to the proper creamy texture.
If you have a batch of gelatin-rich homemade stock stored in your freezer, use that. Otherwise, go with our standard method for lending richness to thin, store-bought broth by enriching it with unflavored gelatin. Bring everything to a boil, then transfer the skillet to the oven to finish cooking. The potatoes soak up a good amount of the stock, which also reduces into a spoon-coating sauce. Once the potatoes are fully tender, remove them to a serving platter and finish the sauce on the stovetop, adding a little more stock if needed to achieve a smooth emulsion. This is a simple show-stopper of a side that proves that French doesn’t have to mean fussy.
Adjust oven rack to middle position and preheat oven to 450°F (230°C). Place stock in a liquid measuring cup or small bowl and sprinkle gelatin over top. Set aside.
Using a sharp knife, cut off ends of potatoes to give them flat sides, then halve potatoes crosswise. Pat dry with paper towels.
In a 12-inch stainless steel straight-sided sauté pan or skillet, or cast iron skillet, heat oil or fat over medium-high heat until just beginning to smoke. Season potatoes with salt and pepper and add to skillet, broad side down, in a single layer with space between each piece. Cook, without moving, until potatoes begin to brown around edges, 4 to 5 minutes. Continue to cook, rotating and swirling pan gently to promote even browning and prevent sticking, until potatoes are deeply browned on bottom side, 3 to 4 minutes longer, adjusting heat as needed if some of the pieces brown too quickly.
Using a thin metal spatula, flip potatoes onto second flat side. Add butter and cook, swirling constantly, until butter is melted and begins to foam, about 1 minute. Add garlic and thyme, and cook until fragrant, 30 seconds to 1 minute. Add stock and bring to a boil.
Transfer skillet to oven and roast until potatoes are completely tender, offering little to no resistance when poked with a paring knife, and liquid is reduced to a saucy consistency, 25 to 30 minutes.
Return skillet to stovetop. Using a thin metal spatula or tongs, transfer potatoes to a serving platter, broad side up, leaving sauce in the skillet; discard garlic. Bring sauce to a simmer over medium heat and cook, swirling and stirring constantly, until sauce is emulsified, 30 seconds to 1 minute. If emulsion appears broken or sauce is too thick, add more stock or water, 1 tablespoon (15ml) at a time, until you reach the desired consistency. Season to taste with salt and pepper and pour sauce over and around potatoes. Sprinkle with flaky sea salt (if using, otherwise season with a little more kosher salt), and serve.
12-inch straight-sided sauté pan or cast iron skillet.
If you happen to have any schmaltz, rendered beef, or duck fat available, we recommend using it for browning the potatoes in place of vegetable oil in step 3.
Make-Ahead and Storage
This dish is best enjoyed immediately, but leftovers can be refrigerated in an airtight container for up to 3 days. Reheat with additional stock, up to 1/4 cup (60ml), to loosen and then re-emulsify the sauce.
Sasha Marx February 24, 2022 at 10:14PM