Karen- In your Albacore Tuna Melt you call for Asiago cheese.Since you instruct to grate it,does that mean that you used the aged rather than the semi soft fresh?If I can't find the asiago what would be a good sub?

I accidently bought fresh Ahi instead of tuna.Oops!Could I substitute the fish or not?If not, do you have a suggestions for Ahi seared rair? That's the way I like it. Thanks-Joyce.