Chicken Salad with chestnuts

1 1/2 cups buttermilk dressing (prepared) 1/2 cup mayonnaise 3 tablespoons half-and-half 1 3/4 teaspoons beau monde seasoning salt and pepper 1 1/2 lbs[...]

1/4 cup low-fat mayonnaise 1/4 cup low-fat sour cream 1/2 cup plain yogurt 1 1/2 teaspoons all-purpose flour 1/2 cup nonfat milk 1 tablespoon lemon juice 2[...]