Fish is done when it's opaque all the way through and the flesh flakes apart easily with a fork — no translucent or glossy raw bits in the center. For most fish, this happens faster than you'd expect, often in just 8–12 minutes depending on thickness. Here's the why: fish muscle is delicate and cooks quickly because it has less connective tissue than chicken or beef. Once the proteins set (turn opaque), you're there. Keep cooking past that point and it dries out fast, so timing matters more with fish than almost any other protein. The easiest test is the fork-flake method — gently press the thickest part of the fillet with a fork at a 45-degree angle. If it flakes into natural pieces and there's no resistance or moisture beading up, you're golden. If it still feels firm and doesn't separate, give it another minute or two. You can also peek inside a thick fillet by making a small cut at the thickest point — the flesh should be opaque, not shiny. One pro move: pull fish off heat about 30 seconds before it looks fully cooked. The residual heat keeps cooking it while it rests, and you'll land it in that sweet spot where it's moist inside instead of chalky.
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