Ellen Krueger's Potato Latkes Recipe from "America Test Kitchen"

Ellen says:
This is an America’s Test Kitchen Recipe.
It’s mostly what I do, so I’ll pass it off as my recipe. ☺

Enjoy.

Potato Latkes
Makes approximately 14 3-inch pancakes.  

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Ingredients

2  pounds Yukon Gold potatoes or russet potatoes, peeled or not
1   medium yellow onion , peeled and cut into eighths
1   large egg
2    tablespoons matzo meal (optional) or flour
1 Tsp baking powder
1 1/2  teaspoons table salt
Ground black pepper
1 cup vegetable oil for frying

Instructions

1. Grate potatoes in food processor fitted with coarse shredding blade. Place half the potatoes in fine mesh sieve set over medium bowl and reserve. Fit food processor with steel blade, add onions, and pulse with remaining potatoes until all pieces measure roughly 1/8 inch and look coarsely chopped, 5 to 6 one-second pulses. Mix with reserved potato shreds in sieve and press against sieve to drain as much liquid as possible into bowl below. Let potato liquid stand until starch settles to bottom, about one minute. Pour off liquid, leaving starch in bowl. Beat egg, then potato mixture and remaining ingredients (except oil), into starch.
 

 2. Meanwhile, heat 1/4-inch depth of oil in 12-inch skillet or sauté pan over medium-high heat until shimmering but not smoking. Working one at a time, place 1/4 cup potato mixture, squeezed of excess liquid and pressed into 1/2-inch thick disc, in oil. (I pick the mixture up with a slotted spoon and press with another spoon on top to remove more moisture before putting in the oil.) Press gently with nonstick spatula; repeat until five latkes are in pan.

 3. Maintaining heat so fat bubbles around latke edges, fry until golden brown on bottom and edges, about three minutes. Turn with spatula and continue frying until golden brown all over, about three minutes more. Drain on a triple thickness of paper towels set on wire rack over a jelly roll pan. Repeat with remaining potato mixture, returning oil to temperature between each batch and replacing oil after every second batch. (Cooled latkes can be covered loosely with plastic wrap, held at room temperature for 4 hours, transferred to a heated cookie sheet and baked in a 375-degree oven, until crisp and hot, about 5 minutes per side. Or, they can be frozen on cookie sheet, transferred to zipper-lock freezer bag, frozen, and reheated in a 375-degree oven until crisp and hot, about 8 minutes per side). Season with salt and pepper to taste and serve immediately.