I had the BGE up to 500.
Cooked the tuna for about 4 minutes per side.
I did overcook it a bit more than I wanted. But it did not take away from being damn tasty. Was like eating a slightly flaky steak.
I am not kidding when I say it tasted just like a great steak.
I have not done asparagus on the grill yet. I really want to, just have not gotten around to it.