Fish should always be cooked as soon as you can. The longer it sits the more it loses it's freshness. If they are frozen you should take them out the night before that should be enough to thaw it in the fridge. To sear it no more than 5 minutes on one side in a pan on high heat. You need to let it sit in the pan to get a solid sear for at least 3 minutes but then check after to see how the sear is coming. Often you can tell by looking at the outer edges. Hope that helps.