Thin cuts of meat or fish need not much more than 1 minute each side in a frying pan or under the grill, and providing you don’t leave them lying around to dry up and curl at the edges, are probably the best bet for the quick cook. Fresh fish is perhaps at its best grilled or fried quickly and served with lemon juice squeezed over it. Farmed salmon is much helped by lime.
You can buy the meat ready slivered: salmon is sold by supermarkets in similar escalopes, but unless you go to a fishmonger you are unlikely to get other fish cut as thinly. Whatever meat you buy, just fry it briefly in butter or oil, deglaze the pan with whatever you want, and pour the juices over.