Creamy Tarragon Chicken Salad

Preheat oven to 450 degrees F.

Arrange chicken in a glass baking dish large enough to hold it in a single layer. Pour broth around the chicken. Bake the chicken until no longer pink in the center and an instant-read thermometer inserted in the thickest part of the breast registers 170 degrees F, 30 to 35 minutes. Transfer the chicken to a cutting board until cool enough to handle, then cut into cubes. (Discard broth or save for another use).

Meanwhile, spread walnuts on a baking sheet and toast in the oven until lightly golden and fragrant, about 6 minutes. Let cool.

Stir sour cream, mayonnaise, tarragon, salt and pepper together in a large bowl. Add celery, grapes, the chicken and walnuts; stir to coat. Refrigerate until chilled, at least 1 hour.