In a large mixing bowl, using a silicone whisk or spatula to combine the pistachio pudding mix and crushed pineapples. Stir until the pudding mix is completely dissolved.
Add the mini marshmallows, chopped walnuts, and cool whip. Fold to combine, ensuring the ingredients are evenly distributed.
Cover the salad with plastic wrap and allow it to chill for an hour in the fridge.
Serve and enjoy!
Notes
We like to top our salad with some chopped pecans, walnuts, or pistachios along with a maraschino cherry.
You can store your watergate salad in the fridge for up to a week when covered with plastic wrap or transferred to an airtight container. We like to give the salad a quick stir before serving to make sure the ingredients are evenly distributed.
Thawed cool whip is much easier to work with, but it is not completely necessary.
You can mix in a frozen cool whip but it will take a little bit longer.