Prep the chicken. Pat the chicken dry with paper towels. Drier chicken = better browning. Cut into evenly sized 1-inch pieces for a fast, even cook.
Season like you mean it. In a bowl, toss the chicken with salt, pepper, smoked paprika, and onion powder. Make sure every piece is coated. No bland bites on our watch.
Heat your pan properly. Set a large skillet over medium-high heat. Add olive oil and let it shimmer—hot oil is your friend for that sear.
Sear in batches. Add half the chicken in a single layer. Don't crowd the pan. Cook 3–4 minutes, undisturbed, until edges are golden. Flip and cook another 2–3 minutes until cooked through. Transfer to a plate; repeat with remaining chicken.
Butter-garlic time. Reduce heat to medium-low. Add butter to the skillet. Once melted and foamy, add garlic and red pepper flakes. Stir 30–45 seconds until fragrant—don't let it brown.
Bring it together. Return all chicken to the pan. Toss in the garlic butter. Add lemon juice and parsley. Taste and adjust seasoning—maybe a pinch more salt or a squeeze more lemon.
Serve immediately. Finish with extra parsley and lemon wedges. Hot rice, mashed potatoes, or a crisp salad are elite pairings, IMO.