Pour 1/2 cup buttermilk into a large resealable plastic bag; add chicken. Seal bag and turn to coat. Place flour in another resealable plastic bag. In a third bag, combine the cornflakes, onion powder, garlic salt, salt, oregano, and pepper. In a shallow bowl, whisk Eggland’s Best eggs and remaining buttermilk.
Drain chicken; add to flour and shake to coat. Coat with egg mixture, then add to cornflake mixture and shake to coat. Arrange chicken in a greased 15-in. x 10-in. baking pan.
Bake at 350º for 10-15 minutes or until juices run clear. In a small bowl, combine apricot preserves and mustard. Serve with chicken.