Pommes Souffles (puffed potatoes or souffleed potatoes)
According to Larousse Gastronomique, the story goes that they were accidentally discovered in 1837 at the inauguration of a new railway line from Paris to Saint-Germain-en-Lay. There was to be a lunch for the dignitaries at the restaurant in the new station. The train was had problems making it up a steep slope at the final approach to the station. The chef prepared some sliced fried potatoes at the appointed time, but when the guests didn't arrive on time, he had to remove the half cooked potatoes and allow them to drain and cool. After several attempts the train finally made it, and caught by surprise at the unexpected arrival of the guests, the chef plunged the potatoes quickly into very hot oil and to his amazement, saw them puff up.
Souffle potatoes must be cooked twice. Once at a low temperature (325) and a second time at a high temperature (375).
At the second high temperature cooking the surface of the potatoes crisp instantly and form a waterproof skin, which will cause them to swell as the moisture inside turns quickly to steam causing the slices to puff up.
The age of the potatoes is important. New potatoes have too much moisture and will not puff, and old potatoes that are soft will not puff.
Cut potatoes in slices 1/4 to 3/8 inch thick, and soak the sliced potatoes in ice water for at least 25 minutes.
Drain them thoroughly and dry them thoroughly.
Have 2 pans with oil on the stove, each with about 3 inches of oil. Heat one to 325 degrees and the other to 375 degrees.
Carefully drop the slices into the 325 degree oil and cook for 6 to 7 minutes, either shaking the pan or moving the potatoes around with a long handled utensil The potatoes should begin to blister after about 5 minutes and rise to the top - continue cooking for an additional 1 minute.
Using a slotted spoon or skimmer, remove the potatoes and drain on paper towels until they begin to soften.
At this point the potatoes may be cooked the second time or held at room temperature for several hours for later service.
To cook the second time, return the potatoes to the 375 degree oil - they should swell instantly. DO NOT PUT TOO MANY POTATOES IN THE 375 degree oil at once - the oil MUST remain very hot for the potatoes to puff. Cook until golden brown, moving them around in the oil - remove and drain on paper towels, discarding any slices that have not puffed.