Pat fillets dry with paper towels — moisture kills your sear. Season both sides with salt and pepper. Lightly coat with olive oil and a squeeze of lemon if desired. For a light crust, shake fillets in a bag with flour, salt, and pepper. Prep all seasonings and sauce ingredients before you start — tilapia cooks fast. Let fillets sit out a few minutes to approach room temperature while you heat the pan.

Heat a large stainless steel or cast iron skillet over medium to medium-high heat. Add enough olive oil to coat the bottom and let it heat until shimmering. Lay fillets in without crowding. Cook undisturbed 2–4 minutes on the first side until browning creeps up the edges and the flesh is opaque halfway up. If the fish resists the spatula, wait another 30–60 seconds — it will release cleanly when ready. Flip and cook the second side 2–4 minutes. Total time: 6–10 minutes depending on thickness. For fillets over 1½ inches thick, transfer the skillet to a 350°F oven after the first sear to cook through without over-browning.

Tilapia is done when it flakes easily with a fork and the flesh is fully opaque with no translucent areas. Target 140°F internal temp — check with an instant-read thermometer in the thickest part. Remove from pan, rest on a warm plate for 1–2 minutes. Pull from heat the moment it flakes; it dries out fast past the doneness window. Serve with fresh lemon or deglaze the pan with white wine, tomatoes, capers, and butter for a quick pan sauce.