Chicken, Grape, and Rice Salad

1 ⅔ cups water

1 tablespoon margarine

1 (5 ounce) package long grain and wild rice mix (such as Mahatma®)

4 cooked chicken breast halves, chopped

½ red onion, chopped, or to taste

1 ½ cups seedless red grapes, quartered

½ cup cashews

¾ cup mayonnaise

Bring water and margarine to a boil in a saucepan; reduce heat to low and stir in long grain and wild rice mix. Cover and simmer until rice is tender, about 25 minutes. Fluff with fork and allow rice mix to cool thoroughly.

Mix cooled rice mix with chicken, red onion, grapes, cashews, and mayonnaise. Serve immediately or chill before serving.