Pat fillets completely dry with paper towels — moisture causes steaming, not searing. Season both sides with salt and black pepper; add lemon juice and dried herbs like oregano or basil if desired. Rest at room temperature a few minutes while you heat the pan. Thick fillets (over ½ inch) need a minute or two extra per side. Have a wide spatula ready — tilapia is delicate and breaks with a narrow tool.

Heat a large skillet over medium to medium-high heat with 1–2 tbsp olive oil until it shimmers. Lay fillets in without crowding and press gently flat for a few seconds. Cook undisturbed for 3 minutes — if the fillet sticks, wait another 30 seconds before flipping. Flip with a wide spatula and cook the second side for another 3 minutes. Total time is 6–10 minutes depending on thickness; thicker fillets may need 4–5 minutes per side. Fish is done when it flakes easily, the flesh is fully opaque, and an instant-read thermometer reads 140°F at the thickest part.

Pull fillets at 140°F internal or when fish flakes easily with a fork. Remove from the pan immediately — tilapia holds little residual heat and only needs 1–2 minutes to rest. Leaving it in the hot pan will overcook it fast. Don't rely on color alone; use the flake test and a thermometer. Finish with a squeeze of fresh lemon, or swirl a small knob of butter in the hot pan and spoon it over. Serve right away while the crust holds.