TO PREPARE THE CROUTONS: Spray a baking sheet with 3 sprays of the olive oil spray or nonstick cooking spray. Spread the bread cubes on the sheet and spray lightly again 3 times. Place in a preheated 350-degree F oven about 20 minutes, or until golden. Remove from the oven and cool.
TO PREPARE THE SALAD: Place the chicken in a pan and cover with water. Bring just to a boil, cover and reduce the heat to medium-low. Cook 10 minutes, or until chicken is cooked through. Remove from the liquid and cool. Cut into small chunks or pull into shreds.
Combine the chicken with the celery, raisins and lemon peel.
TO PREPARE THE DRESSING: In a bowl, stir together the yogurt, mayonnaise, lemon juice, mustard, honey, rosemary, salt and pepper. Stir into the salad, cover and refrigerate until ready to serve.
Wash the romaine and radicchio, pat dry and wrap in paper towels. Refrigerate.
When ready to serve, stir together 2 teaspoons lemon juice and 1 teaspoon olive oil. Tear the lettuce into small pieces and toss with the lemon-oil mixture. Divide between plates and top with the chicken salad. Garnish with the croutons.
Note: If radicchio is unavailable or too expensive, substitute red leaf lettuce.