Why It Works
- Arranging the chicken thighs around the border of the sheet pan puts them where the heat is highest, leading to crispy brown skin while protecting the potatoes and fennel below from scorching.
- Skin-on chicken thighs render their fat onto the vegetables for absolutely delicious results.
- A quick pan sauce makes the most of the chicken juices left on the sheet pan.
This easy sheet-pan dinner manages to pull out all the stops, delivering tender chicken thighs with crispy skin, a potato-fennel gratin that's in turn creamy and crispy, and a dead-simple "sheet-pan" sauce that amounts to little more than popping open a can of beer and stirring in some mustard. The secret to its success lies in its architecture: knowing just how to cut and arrange everything to get the kind of killer results most cooks would trash their kitchen with cookware and bowls to pull off.
For starters, we slice the potatoes and fennel thinly and layer them in an even scalloped design. This isn't just for appearance's sake—it dramatically changes how the vegetables cook. The thin slices keep the vegetables close to the sheet-pan floor, and as the chicken fat renders, it bathes them more fully than it would if they'd been cut into larger chunks. This makes the vegetables unbelievably creamy and tender while still browning and crisping them on the surface, especially after some Cheddar cheese gets grated on top and flash-cooked under the broiler.
That crispy, cheesy surface is another key point. By spreading the vegetables in such a large, even layer, you maximize surface area for browning and cheese coverage. Then, when transferred to a serving platter or plates, you can stack sections of the thin layer of scalloped vegetables on top of each other to make them more like a traditional gratin cooked in a deeper baking dish with crisp and cheesy bits hidden within.
The choice of chicken itself is key, too, since thighs and legs can handle longer cooking without drying out the way white meat does. This offers ample time for the meat to hang out in the oven as the skin browns and becomes crackling, all while the fat melts and bathes the vegetables underneath. Arranging the chicken along the edges of the pan is equally important, keeping it where the pan gets hottest so that the skin browns and crisps as much as possible while protecting the potatoes and fennel below.
We could have stopped there, but just for fun, we decided to whip up a quick "sheet-pan" sauce after the chicken and vegetables had been transferred to serving plates. All you have to do is heat the empty sheet pan over a burner to brown the remaining chicken juices and deepen their flavor; then deglaze it with a can of beer. Stir in some old-fashioned mustard and a bit of sugar to balance out the beer and mustard's bitterness, add a couple tablespoons of butter, and it's ready to be drizzled on top.
- 1 1/2 pounds (680g; about 3 large) Yukon gold potatoes, sliced crosswise into 1/8-inch-thick rounds
- 1 large (1 pound; 450g) bulb fennel, stalks, and root end trimmed and bulb sliced lengthwise 1/8-inch-thick, fronds reserved
- 1 tablespoon extra-virgin olive oil
- Kosher salt and freshly ground black pepper
- 8 bone-in, skin-on chicken thighs (about 3 pounds/1.3kg; see note)
- 4 ounces (115g) sharp white Cheddar cheese, finely grated, preferably with a Microplane grater
- One (12-ounce; 355ml) can lager, pilsner, or pale ale
- 3 tablespoons (45ml) stone-ground (coarse) mustard
- 1 teaspoon sugar, or more to taste
- 2 tablespoons (30g) unsalted butter
Preheat oven to 450°F (230°C) and set rack in upper-middle position. In large mixing bowl, toss potatoes and fennel with olive oil. Season lightly with salt and pepper.
On a rimmed baking sheet, arrange potatoes and fennel in even layers that are slightly overlapping, covering the entire surface of the baking sheet. You can try to make a pretty scalloped pattern, though it's not essential that the design be beautiful.
Season chicken all over with salt and pepper. Arrange chicken along outer edges of the sheet pan, making sure there's a thigh covering every corner (the baking sheet gets hottest at the edges and corners, so placing chicken there will keep the potatoes below from scorching).
Bake chicken and vegetables until chicken skin is golden and crispy, about 45 minutes. Transfer chicken thighs to warm serving platter or plates and keep warm.
Scatter grated cheese all over the surface of the potatoes and fennel. Turn the oven to broiler mode. Broil until cheese is melted and turning lightly golden in spots and vegetables grow slightly more crisp and brown on the surface, about 5 minutes.
Using a slotted spatula, carefully transfer potatoes and fennel to serving platter or plates, allowing excess fat to drain before each transfer. You can stack vegetables on top of each other to create a taller gratin-like structure. Keep warm.
Set baking sheet over stovetop burner set to medium-high heat. Cook, moving the baking sheet around as needed, to brown remnant cooking juices on the bottom of the baking sheet; be careful not to accidentally burn your potholder or kitchen towel as you maneuver the baking sheet around over the flame. Also don't be alarmed if your baking sheet buckles; this can happen when it undergoes big temperature shifts, and we've always found they return to their normal flat shape soon.
Drain excess fat on the baking sheet into a small heatproof bowl. Return baking sheet to heat and immediately add beer. Increase heat to high and bring beer to boil. Using a wooden spoon, scrape up the browned bits on the bottom of the baking sheet.
Stir in mustard, using wooden spoon. Work mustard into the beer while carefully shaking the baking sheet to mix the thin layer of liquid on it. Continue to cook, stirring and gently shaking, until reduced by about half. Stir in sugar. Turn off heat and melt in butter, stirring and shaking the whole time to emulsify it into the sauce. Taste, then season with salt and/or more sugar, as desired. Pour sauce into serving boat. Garnish potatoes with reserved fennel fronds and serve.
You can also substitute 4 chicken legs, whole or split into drumsticks and thighs.