Toast the pecans in a dry skillet over medium heat for 4-6 minutes, stirring frequently, until fragrant. Alternatively, spread them on a baking sheet and toast at 350 °F (175 °C) for 5-8 minutes, stirring once. Let cool completely.
1/2 cup pecans
In a small bowl, whisk together the mayonnaise, sour cream, lemon juice, Dijon mustard, salt, and black pepper until smooth.
1/2 cup mayonnaise, 1/4 cup sour cream, 1 tablespoon freshly squeezed lemon juice, 1 teaspoon Dijon mustard, 1/4 teaspoon salt, 1/4 teaspoon cracked black pepper
In a large mixing bowl, combine the chicken, grapes, celery, green onions, parsley, and cooled pecans (if making this to serve in advance, reserve the pecans and stir in before serving).
3 cups cooked, cooled, and diced chicken, 1 1/2 cups seedless red grapes, 1/2 cup celery,, 1/4 cup green onions, 1 tablespoon fresh flat-leaf parsley, 1/2 cup pecans
Pour the dressing over the chicken mixture and stir gently until everything is evenly coated.
Cover and refrigerate for at least 30 minutes before serving.
Stir gently before serving. If the salad is very cold, let it sit at room temperature for 5-10 minutes first.
For the best texture, prepare the chicken salad no more than 24 hours before serving. Keep it tightly covered in the refrigerator and stir it gently before serving. Store the chicken salad in an airtight container in the refrigerator for up to 3 days from the day it was prepared. For the best flavor, let the chicken salad sit at room temperature for about 5-10 minutes before serving so it isn’t extremely cold straight from the refrigerator. The dressing should remain creamy for up to 3 days, but the pecans will gradually soften and the grapes may release a little moisture as it sits. Do not freeze.