1 1/2 cups panko bread crumbs
1/4 cup olive oil
kosher salt and black pepper
1/4 cup all-purpose flour
2 large eggs, lightly beaten
1 small sweet onion (such as Vidalia or Walla Walla), sliced and rings separated
3/4 cup buttermilk
1/3 cup mayonnaise
1 teaspoon chopped chipotles in adobo sauce
2 tablespoons finely chopped fresh parsley

1 1/2 cups panko bread crumbs 1/4 cup olive oil 1/4 cup all-purpose flour 2 large eggs, lightly beaten 1 small sweet onion (such as Vidalia or Walla Walla), sliced and rings separated 3/4 cup buttermilk 1/3 cup mayonnaise 1 teaspoon chopped chipotles in adobo sauce 2 tablespoons finely chopped fresh parsley

1.Heat oven to 450° F. Toss the bread crumbs with 2 tablespoons of the oil, ½ teaspoon salt, and ¼ teaspoon pepper. Bake on a rimmed baking sheet, tossing once, until golden brown, 3 to 5 minutes. Transfer to a shallow bowl. Place the flour and eggs each in separate shallow bowls.
2.Rub the remaining oil on 2 rimmed baking sheets. Dip the onion rings in the flour and eggs (letting any excess drip off), then coat with the bread crumbs, pressing gently to help them adhere. Bake on the prepared baking sheets, turning once, until tender, 12 to 14 minutes.
3.Whisk together the buttermilk, mayonnaise, chipotles, parsley, and ¼ teaspoon salt in a small bowl. Serve with the onion rings for dipping