PreparationMake the apple-horseradish mayonnaise: In a medium bowl, stir together the horseradish, applesauce, vinegar, mustard, and mayonnaise. Season with salt and pepper. DO AHEAD: The sauce can be made and stored, in an airtight container in the refrigerator, up to 3 days. Make the latkes: Line a large bowl with a clean cloth napkin or lint-free kitchen towel. Working in batches, use the larger side of a box grater or a food processor fitted with a grater attachment to coarsely grate the potatoes, Jerusalem artichokes, and onion. As they're grated, transfer the vegetables to the towel-lined bowl. Gather the corners of the towel and wring as much excess liquid as possible from the vegetables. Transfer the wrung vegetables to a dry mixing bowl. Add the egg and parsley and stir to combine. While stirring the mixture, gradually add the flour, stirring well to incorporate. Line a large baking sheet with paper towels. In a large sauté pan over moderately high heat, heat 1/4 inch of oil until hot but not smoking. Test the latke batter by frying a small amount of batter in the hot oil—it should hold together and not fall apart when flipped. If necessary, add additional flour, 1 tablespoon at a time, but try to add as little flour as possible to create light latkes. Working in batches, drop 2-tablespoon-size dollops of batter into the hot oil and use the back of a spoon to press the batter into 1 1/2-inch diameter pancakes. Season with salt and pepper and fry until golden brown, about 2 minutes. Flip the latkes and continue frying until golden brown, about 2 minutes. As they finish cooking, transfer the latkes to the paper-towel-lined baking sheet. To serve: Arrange the latkes on a large plate or platter and top half with apple-horseradish mayonnaise and half with taramasalata. Sprinkle with minced chives and serve immediately.
PreparationMake the apple-horseradish mayonnaise: In a medium bowl, stir together the horseradish, applesauce, vinegar, mustard, and mayonnaise. Season with salt and pepper. DO AHEAD: The sauce can be made and stored, in an airtight container in the refrigerator, up to 3 days. Make the latkes: Line a large bowl with a clean cloth napkin or lint-free kitchen towel. Working in batches, use the larger side of a box grater or a food processor fitted with a grater attachment to coarsely grate the potatoes, Jerusalem artichokes, and onion. As they're grated, transfer the vegetables to the towel-lined bowl. Gather the corners of the towel and wring as much excess liquid as possible from the vegetables. Transfer the wrung vegetables to a dry mixing bowl. Add the egg and parsley and stir to combine. While stirring the mixture, gradually add the flour, stirring well to incorporate. Line a large baking sheet with paper towels. In a large sauté pan over moderately high heat, heat 1/4 inch of oil until hot but not smoking. Test the latke batter by frying a small amount of batter in the hot oil—it should hold together and not fall apart when flipped. If necessary, add additional flour, 1 tablespoon at a time, but try to add as little flour as possible to create light latkes. Working in batches, drop 2-tablespoon-size dollops of batter into the hot oil and use the back of a spoon to press the batter into 1 1/2-inch diameter pancakes. Season with salt and pepper and fry until golden brown, about 2 minutes. Flip the latkes and continue frying until golden brown, about 2 minutes. As they finish cooking, transfer the latkes to the paper-towel-lined baking sheet. To serve: Arrange the latkes on a large plate or platter and top half with apple-horseradish mayonnaise and half with taramasalata. Sprinkle with minced chives and serve immediately.