If you really need extra flavor beyond that provided by a tuna steak, you can always make some sort of dipping sauce (an Asian-inspired combination of ingredients like soy sauce, ginger ...

Add the mushrooms, pepper, onion, garlic, rocket, carrot and tuna to a bowl ... Enjoy as a snack with sweet and sour sauce or make a more substantial meal by serving with rice.

Take the tuna from the pan and place it on a cutting board and let it rest briefly. Slice it about 8mm (⅜in) thick and put the pieces on plates. Spoon some of the sauce over each portion ...