Place potatoes in a pot and cover with water until it's about 2 inches above the potatoes.
Add 1 tsp of salt and stir.
Bring the pot to a boil and continue to cook until the potatoes are tender.
Once cooked, drain the potatoes in a colander and let them dry for about 10 minutes.
After drying, put the potatoes in a large bowl and crush them with a sturdy whisk. Don't overbeat them - you want them crushed, not mashed. Add some of the cream while doing this to help break the potatoes down.
Fold in the horseradish sauce, remaining cream, butter, lemon juice, lemon zest, parsley, sour cream, another tsp of salt, and ground black pepper. Be careful not to over whip - you're aiming for a chunky, creamy texture rather than a smooth one.
Once everything is combined, let the mixture cool. Your Horseradish Crushed Red Potatoes are now ready to serve!