2 1/2 pounds Idaho, russet or baking potatoes (about 4 large), scrubbed
1 large onion, peeled and quartered
2 large eggs, separated
3 tablespoons matzoh meal or bread crumbs
1 to 2 teaspoons kosher salt
1 teaspoon black pepper
Corn or canola, or vegetable oil for frying
Line a large baking sheet with two layers of paper towels; set aside.