Cod & tuna

Let's start with tuna. It's a bit easier. You can do it like a steak. Leave it out for half an hour to get close to room temp. A little rub of olive oil. A bit of dry rub or just salt and pepper. Get the egg hot. I'd do 500-600. One minute max per side for a 1-inch cut. Maybe 2 minutes per side for a 2-inch cut.

Cod is a bit trickier just because it's more fragile. Maybe a brush with melted butter. Again, apply dry rub of your preference. I'd cook it on a hot griddle or small cast iron pan on the egg. Maybe 2 minutes per side. Turn carefully. Alternatively, if you have a cedar plank, you could do the cod on that. No need to turn. Yeah, that would be the way to go!