How to Make It
With a mixer using the whisk attachment, whip cream and cream cheese on medium speed until whisk just begins to leave marks, about 4 minutes. Remove from mixer and add horseradish, pepper, 2 tsp. lemon juice, and 1/2 tsp. salt. Whisk by hand to blend and thicken. Taste and add more salt and lemon juice if you like.
Make ahead: Up to 2 days, chilled. Whisk to refluff, and add a little more cream to loosen.