Thaw the tuna at room temperature. Pepper the steaks. Fry vigorously for 2 minutes on each side. Take out of the pan. Salt. Peel the lemon, cut into slices and add to the remaining frying fat. Braise briefly. Add the cream. Possibly stir in a pinch of sugar. Pour over the steaks.
I also had boiled potatoes that I tossed in butter after cooking.