Line a colander with paper towel.
Peel and cut potatoes and place them in cold water
Using a whisk, in a large bowl, mix all ingredients except the potato, onion and oil – until frothy. Set aside
Using the fine grater on your food processor, alternate grating potatoes and onions, a bit of each at a time until the food processor bowl is quite full.
Switch to steel blade and make a few course chops to break up the potatoes/onions even more.
Transfer the onion/potatoes to the colander and, over the sink using the paper towel, squeeze the liquid out.
Transfer the drained onion/potatoes to the large bowl and mix well with egg/flour mixture.
Heat half the oil and add latke mixture by tablespoons, frying until well browned on both sides. Do not ccrowd the pan, no more than 6 at once. REpeat with the remaining latke mixture adding additional oil as needed.