If you are going with the frozen just leave them in the shrink wrap and put them in a bowl of cold water and let them thaw for about 5-8 minutes. Cut the plastic shrink wrap off, toss the water and put the filets back in the bowl with the juice and rind of a lemon and the chopped mint leaves.
Let them sit while you put a skillet on at medium high and eyeball just enough olive oil to coat the bottom of the skillet. When the skillet is hot put the tuna steaks in. An option here is to add a pad of butter and/or a splash of white wine. But, that's up to YOU.
Rare is about a minute to a minute and a half a side and medium well is about 2 and a half to 3 minutes a side depending on the thickness of your filets. Tonight we did them medium well because that's the way Gammy likes hers...I'm learning.
You could zap some potatoes in the microwave and throw together a quick salad while the steaks are cooking .