Prep the salmon: Pat the fillets dry with paper towels. This helps them sear instead of steam. Season both sides with salt and pepper.

Make the lemon-garlic butter: In a small bowl, combine softened butter with minced garlic, lemon zest, and a pinch of salt. Stir in parsley and red pepper flakes if using. Set aside.

Preheat your pan: Heat a large skillet over medium to medium-high heat. Add olive oil and let it shimmer. You want the pan hot enough to sear, but not smoking.

Sear the salmon: Place the salmon in the pan, skin-side down if using skin-on fillets. Press lightly with a spatula for the first 10 seconds so the skin makes full contact. Cook for 4–5 minutes, until the sides look opaque about halfway up.

Flip and baste: Flip the salmon carefully. Dot each fillet with the lemon-garlic butter. As it melts, tilt the pan and spoon the butter over the fish. Cook another 2–4 minutes, depending on thickness, until the centers are just translucent or reach about 125–130°F for medium.

Add lemon juice: Squeeze fresh lemon juice over the salmon during the last 30–60 seconds. It will sizzle and mix with the butter to make a quick pan sauce.

Rest and serve: Transfer salmon to plates and spoon any remaining sauce over the top. Garnish with extra parsley and lemon slices. Serve with rice, roasted potatoes, or a crisp salad.

Optional oven method: For a hands-off version, arrange seasoned salmon on a lined sheet pan. Spread the lemon-garlic butter over the top. Roast at 400°F for 10–12 minutes, or until just cooked through. Finish with a squeeze of lemon.