For a lighter version than the original, this egg salad uses more whites than yolks and a dash of Madras curry to boost the flavor.
Mix whites, yolks, mayonnaise, celery, mustard, and curry if desired. Season with salt and pepper. Spread mayonnaise on 4 slices bread. Top each with radicchio, egg salad, and arugula if desired. Sandwich with remaining bread.
For best results, use organic eggs and thinly sliced bread to enhance the bright-yellow salad made crunchy with celery and radicchio.