Bring a saucepan of water to boil. Have a bowl of cold water ready. Make a cross with a sharp knife on the bottom part of the tomato. Plunge the tomatoes into the boiling water for a few seconds — until the skins wrinkle slightly. With a slotted spoon, transfer them to the cold water bowl. This will help to loosen the skins. Drain off the water and peel away the skins.
A quick way of removing the skins for sauces is to cut a cross on the bottom of the tomato. Push that side against the large holes of a grater and grate through, holding the tomato with the palm of your hand. You should be left with most of the tomato skin in your palm.