Cut cheese into 16 slices, each approximately 1/8 inch thick, 5 inches long and 2 inches wide. Boil potatoes just before use, peel and keep hot.
Preheat the oven to 500'F for at least 15 minutes. Heat four 10-inch ovenproof dinner plates in the oven for 3 to 5 minutes. To ensure the success of the raclette, the plates must be very hot.
When redy to serve, remove the plates from the oven, grasping them with potholders, and, as quickly as you can, arrange four slices of the cheese in the center of each plate, overlapping them slightly. The cheese should begin to sizzle as soon as it comes in contact with the plate. At once, place the four plates on the floor of the oven (if you are using an electric oven, place the plates on a rack set in the first slot above the source of heat). In about 2 minutes (5 to 6 minutes in an electric oven) the cheese should melt to a creamy, bubbly mass; do not let it turn the slightest bit brown. Remove from the oven, place a potato and one or two gherkins and pickled onions on the side of each plate and serve at once, setting each plate on a service plate to prevent it from scorching the table.
succession at one sitting. Should you want to do the same, double or triple all the ingredients and have two or three sets of dinner plates heating in the oven while the first batch of raclette is being eaten.