add a little olive oil in a pan, add the steaks and cook over a medium low heat for 4 minutes, Turn the steak and cook for a further 4 minutes. (the tuna steak should be slightly pink inside still.
Remove the Tuna steaks form the pan, keep warm.
in the pan add the butter, once melted add the mushrooms once cooked, push the mushrooms to one side and tip the pan so the butter is on one side add teh flour and mix to a paste and some whole pepepercorns and add a dash of milk, gradually making the paste thinner into a sauce. Mix in the mushrooms, simmer for 2 mins, should give a nice peppery mushroom flavour.
pour over the tuna steaks. and serve. I serve with new potaoes