Bring a large pot of water to a boil. With a sharp paring knife,
cut an X just through the skin on the bottom of each tomato (Notice the
picture above). Drop the tomatoes, a few at a time, into the water
for 30 seconds. Remove the tomatoes with a slotted spoon to a bowl
filled with ice water to cool them down. The skin will easily slip
off each tomato. If the tomatoes are to be cooked further, the ice
water bath is unnecessary.