Warm the garlic oil in a non stick frying pan that will take all the steaks snugly in a single layer. When the oil is hot fry the steaks over a high heat for about 30 seconds on each side ( longer if you must). Remove from the heat and put the steaks on a large piece of foil. Make a loose but tightly sealed parcel.
Return the pan to the heat and add the anchovies, stirring and squishing them down with a wooden spoon until they start to dissolve in the oil. Stir in the dried oregano and chilli flakes.
Tumble in the halved tomatoes, olives and capers , then add the vermouth and cook for a couple of minutes. Add the water and cook for a further minute.
While the sauce is cooking unwrap the steaks and divide between serving plates. Pour any juices that have collected into the pan with the tomatoes and divide the sauce over the steaks, Sprinkle with the parsley.