Chicken, Apple, and Walnut Salad

3 chicken breasts, boned
1/4 C sherry wine vinegar
1 t dried tarragon
1/4 C salad oil
salt and pepper
2 T lemon juice
1 C ice water
3 Granny smith apples, medium-sized
1/2 C walnut halves
2 T butter
Vinaigrette dressing

Cut chicken breasts in half, marinate for 30 minutes in a non-aluminum bowl with vinegar, tarragon, oil, salt, and pepper.
In another bowl, combine lemon juice and water. Peel and core apples and slice into thin wedges. Place in lemon juice mixture and refrigerate.
Place chicken breasts in skillet large enough to hold in a single layer. Add marinade and cook, covered, over moderate heat until done, about 20 minutes, turning a few times (don’t overcook).
Spread walnuts in a single layer in a flat pan. Dot with butter and bake for 15-20 minutes in a 325 degree oven. Shake pan from time to time. Remove when crisp; careful not to burn.
Drain chicken and cut into diagonal slices. Line serving platter with lettuce and arrange chicken in center of platter in concentric circles, slices overlapping.
Drain apples and pat dry. Border chicken with apple slices. Sprinkle with vinaigrette and walnuts. Pass additional vinaigrette.