Prep the chicken: Pat the chicken breasts very dry with paper towels — moisture prevents a good crust. If breasts are uneven in thickness, place each between plastic wrap and gently pound to an even 3/4" thickness (this ensures even cooking). Season both sides generously with 1 tsp kosher salt and 1/2 tsp black pepper.

Make the dredge: On a plate, combine the all-purpose flour with smoked paprika and a pinch (about 1/2 tsp) of the remaining salt. Lightly dredge each breast, shaking off excess. A light flour coating helps create a golden crust and gives the pan sauce a little body from the fond (browned bits) that form while searing.

Heat the pan: Place a large, heavy skillet (cast-iron or stainless steel) over medium-high heat until hot — about 2–3 minutes. Add the olive oil and 1 tbsp of the butter. Heating the fat until shimmering ensures a fast sear that browns without sticking.

Sear the chicken: Add the chicken breasts (do not crowd the pan) and let them sear undisturbed 4–5 minutes until a deep golden crust forms; flip and sear the other side 3–4 minutes. Searing quickly on high heat develops Maillard browning — that deep flavor foundation. If the pan gets too dark, reduce heat slightly so the flour coating doesn’t burn.

Finish in the pan: Lower heat to medium and add the remaining 1 tbsp butter around the chicken; tilt the pan and spoon the melted butter over the tops for 30 seconds to finish (baste). This keeps the meat moist and adds buttery flavor. Transfer the chicken to a plate and tent loosely with foil to rest while you make the sauce — resting lets juices redistribute so the chicken stays juicy.

Sweat the aromatics: Reduce heat to medium. Add the diced onion to the still-warm skillet and cook 2–3 minutes until translucent; this softens the onion and draws out sweetness. Add the minced garlic and cook 30–45 seconds until fragrant — don’t let the garlic brown or it will taste bitter.

Deglaze and build the sauce: Pour in the chicken stock and use a wooden spoon to scrape the browned bits (fond) from the bottom of the pan — those bits are concentrated flavor. Add the lemon juice and dried thyme. Let the sauce simmer gently 3–4 minutes to reduce by about one-third; reduction concentrates flavor and slightly thickens the sauce.

Finish the sauce: Taste and season with the remaining 1/2 tsp kosher salt and the remaining 1/2 tsp black pepper as needed. Swirl in any accumulated juices from the resting chicken and the chopped parsley for freshness. If you want a silkier sauce, lower the heat and whisk in 1–2 tsp cold butter (optional) to emulsify and shine the sauce — butter added off heat rounds the acidity and gives a luxurious finish.

Return chicken to pan and coat: Nestle the chicken back into the pan for 1 minute to rewarm and coat in the sauce. This step melds the flavors and keeps the chicken warm without overcooking.

Serve: Transfer chicken to plates, spoon the lemon-thyme pan sauce over each breast, sprinkle with extra parsley and serve with lemon wedges. The bright lemon cuts the richness and makes the dish feel light and elegant.