I don't have a grill very available, but I do have a Foreman grill.
I did the pan searing thing, similar to what you suggested. Wow, that's good stuff. I usually will only eat tuna raw....but now that I have a way to cook the leftovers that I don't eat raw, I'm gonna eat a lot more tuna.
I mixed coursely ground peppercorns (mix of 5 peppers, mostly black malabar) with a slight amount of butter and a bunch of lemon juice, added in some ground ginger, and some whole black malabar peppercorns....cooked it in the pan till the center was mostly cooked and slightly pink. That turned out really well, good stuff.
I also mixed some sriracha pepper sauce with mayo to make a nice spicy sauce and dipped some of the tuna in that....mmmmmm good.
Thanks a lot for the ideas, you have made my day today. Nothing like starting with a damn good breakfast.
b