Prepare the potatoes: Peel your potatoes. Cut into cubes. Add water to your pot of boiling water, add in your potatoes. Boil for 20 minutes. Remove from water, and mash with fork.
Mix: Add the butter, milk and heavy cream into your mashed potatoes with salt and pepper. Mix well. Add a light sprinkle of celery salt. Mix and taste. Adjust to suit your taste.