Peel 4 pounds of russet potatoes** and slice thinly into 1/8 inch rounds with a sharp knife, mandolin
, or food processor
. See photos. If you have a food processor, I highly recommend using it. The slicer attachment cuts them to exactly the 1/8 inch size you need, and it's so much faster. If there is any lag time in between when you slice the potatoes and when you add them to the sauce, place them in a large bowl of water to prevent browning. Drain well.