Preheat and prep: Preheat your oven to 425°F (220°C). Pat the chicken thighs very dry with paper towels — this helps the skin crisp in the oven because moisture prevents browning. Rub both sides with 1/2 tsp kosher salt and 1/4 tsp black pepper.

Make the lemon-rosemary oil: In a small bowl combine the olive oil, minced garlic, chopped rosemary, lemon zest (from 1 lemon), and 1 tbsp of lemon juice. Whisk to combine. This mixture will both flavor the chicken and help transfer aromatic oils under the skin.

Loosen skin and season under it: Gently slide your fingers between the skin and meat of each thigh to loosen a pocket (use a spoon if easier). Rub half of the lemon-rosemary oil mixture directly on the meat under the skin — this ensures the aromatics are close to the flesh and not just on the surface. Brush the remaining oil on top of the skin. Why: getting flavor under the skin seasons the meat and flavors fat that will baste the thighs as they roast.

Sear if you like extra color (optional but recommended): Heat a 10-inch ovenproof skillet over medium-high heat until shimmering. Place thighs skin-side down and sear 3–4 minutes without moving until the skin is deeply golden — this first high-heat contact jump-starts the Maillard reaction and improves crispness. If you don’t have an ovenproof skillet, sear in a regular skillet and transfer to a baking dish.

Roast the chicken: Transfer the skillet to the oven (or place thighs in a roasting dish) and roast at 425°F (220°C) for 20–25 minutes until an instant-read thermometer inserted into the thickest part away from the bone reads 165°F (74°C). Why: the high oven temperature crisps skin while the thermometer ensures juicy, safe internal temperature without overcooking.

While the chicken roasts — start the potatoes: Put the cubed sweet potatoes in a medium pot and cover with cold water by about 1 inch. Add 1/2 tsp salt. Bring to a boil, then reduce to a simmer and cook until very tender, about 12–15 minutes. Why: starting in cold water cooks the potato evenly; salt seasons through the flesh.

Cook the green beans: When the potatoes have about 6 minutes left, bring a second pot of salted water to a boil. Add the green beans and blanch for 3–4 minutes until bright green and just tender. Immediately transfer to an ice bath or rinse under very cold water to stop cooking and preserve color and snap. Why: blanching stops enzymatic cooking for vibrant color and a crisp-tender texture.

Finish the mash: Drain the sweet potatoes well and return to the hot pot for a minute over low heat to evaporate excess moisture — this helps produce a fluffy mash. Mash with a potato masher (or ricer for extra silkiness) with the butter, 2 tbsp milk, a pinch of salt and pepper, and 1/2 tbsp lemon juice. Taste and adjust: add more milk for creaminess or another pinch of salt for balance. Why: warming the milk/butter slightly before adding helps them emulsify into the potato for a glossy, creamy texture without becoming gluey.

Dress the green beans: Drain the blanched beans and toss with a drizzle (about 1 tsp) of olive oil, a little lemon zest, salt and pepper to taste, and a small pinch of the chopped rosemary if desired. Why: a light toss preserves their snap and adds a linking flavor that ties them to the chicken.

Rest the chicken: Remove chicken from the oven and let rest in the skillet or on a cutting board for 5 minutes. Resting lets juices redistribute so they won’t gush out when you cut. If you like, spoon pan juices over the thighs; you can also squeeze the remaining 1/2 tbsp lemon juice over the chicken to brighten the flavor.

Plate and finish: Spoon a generous portion of mashed sweet potato onto each plate, arrange a roasted thigh beside it, and tuck the green beans alongside. Optionally sprinkle a tiny pinch of smoked paprika over the chicken for color and a whisper of smoke. Serve hot.

Clean-up and leftover tips: Reserve any pan juices — they make a quick sauce. Deglaze the roasting pan with 1/4 cup water or white wine on the stovetop and whisk in the remaining lemon-rosemary oil and a pat of butter for a quick pan sauce.