Take 1/2 cup of cold heavy cream, and whip with a mixer or whisk until it makes 1 cup whipped cream. To make dressing, in a small bowl whisk mayonnaise, lemon juice, and sugar until combined. Gently fold in whipped cream.
Combine fruit, nuts, and celery in a large bowl. Pour dressing on top and gently toss to combine until everything is evenly coated. Transfer to a nice serving bowl and sprinkle marshmallows and nutmeg. Enjoy!