Prepare the chicken and marinade: Pat the chicken thighs dry with paper towels (dry skin/meat browns better). In a bowl combine 1 tbsp olive oil, zest of the lemon, 1 tbsp lemon juice, minced garlic, chopped rosemary, 1/2 tsp kosher salt and 1/4 tsp black pepper. Rub the mixture evenly over the thighs and let rest at room temperature for 20–30 minutes or refrigerate up to 4 hours. WHY: Drying the chicken and letting it marinate allows the lemon and rosemary to flavor the surface while the short rest lets the meat come closer to room temp for even cooking.

Preheat oven and roast the sweet potato: Preheat the oven to 425°F (220°C). Toss the cubed sweet potato with 1/2 tbsp olive oil, a pinch of salt and pepper; spread in a single layer on a rimmed baking sheet. Roast for 20–25 minutes, turning once halfway, until edges are caramelized and the centers are tender when pierced. WHY: High heat caramelizes the sweet potato sugars for deeper flavor and contrast to the savory chicken; spreading in one layer prevents steaming and promotes browning.

Sear the chicken: While the sweet potato begins roasting, heat a 10–12 inch oven-safe skillet over medium-high heat until shimmering. Add the remaining 1/2 tbsp olive oil. If using skin-on thighs, place them skin-side down and press gently for 20–30 seconds to ensure even contact; if skinless, place presentation-side down. Sear 3–4 minutes without moving until a deep golden-brown crust forms, then flip and sear the other side 2 minutes. WHY: Searing creates Maillard browning which builds savory flavor and a pleasing texture that further develops in the oven.

Finish the chicken in the oven: Move the skillet with the seared thighs into the preheated 425°F oven (or transfer thighs to a baking dish if your skillet isn't oven-safe). Roast for 12–15 minutes, or until the thickest part registers 165°F (74°C) on an instant-read thermometer. Add the roasted sweet potato to the pan for the final 8–10 minutes so they finish together. WHY: Roasting after searing cooks the thighs gently and evenly and allows flavors to mingle; checking internal temperature prevents overcooking and ensures safe doneness.

Steam and finish the broccoli: While the chicken roasts, steam the broccoli until bright green and just tender (about 5–6 minutes). Drain and toss with 1 tbsp butter, a squeeze of lemon juice (from the same lemon), a pinch of salt, and a few grinds of black pepper. WHY: A brief steam preserves broccoli’s color, nutrients and crisp-tender texture; finishing with butter and lemon adds richness and lifts the vegetable’s flavor to match the chicken.

Make the pan sauce and rest the chicken: After the chicken reaches temperature, transfer thighs to a cutting board to rest 5 minutes (resting keeps juices from running out when you cut). Place the skillet back on medium heat, add any pan juices, the remaining 1 tbsp butter, and a tablespoon of lemon juice; scrape up the browned bits with a wooden spoon (deglazing). Swirl off heat and taste — add salt or a pinch of red pepper flakes if desired. WHY: Resting redistributes juices for juicier meat. Deglazing captures all the fond (browned flavor) to make a glossy, concentrated sauce that brightens with lemon.

Plate and serve: Halve or leave the thighs whole and arrange on plates with the roasted sweet potato and lemon-butter broccoli. Spoon the lemon-rosemary pan sauce over the thighs and vegetables; finish with a small pinch of flaky sea salt and extra chopped rosemary for color. WHY: Spoon the sauce over everything to unify the components so each bite has balance — acid from lemon, savory from pan jus, sweet from potato and fresh herb notes.

Storage and reheating: Refrigerate leftovers in an airtight container up to 3 days. Reheat gently in a 325°F oven covered with foil until warmed through (about 15 minutes), or reheat sweet potato in a hot skillet to revive caramelization. WHY: Gentle reheating preserves texture; high heat quickly can dry the chicken.