Walnut Chicken Salad

2/3 c. nonfat plain yogurt
1/2 c. finely chopped celery
1/2 c. finely chopped spinach (or about 3 T drained thawed frozen chopped)
1/4 c. chopped green onions
1 T lemon juice
1 t ground mustard
1/2 t dried dill or tarragon
3 C diced cooked chicken breast
1 apple, cored and diced
1/2 c. chopped walnuts
salt and pepper

Combine and chill.
Serve on lettuce or bread, crackers, pita