latkes recipe

1 ½ pounds Russet potatoes (3 to 4 potatoes) ½ medium yellow onion 1 large egg 2 tablespoons unseasoned dry breadcrumbs (or matzo meal) 1 teaspoon kosher salt 0.12 teaspoon freshly ground black pepper 1 cup chicken schmaltz (or canola oil, or a combination of both) Applesauce and sour cream (for serving)