Fill mixing bowl half full with ice and swirl around inside of bowl to chill. Dry thoroughly.
Strain horseradish through a napkin or cheesecloth. Measure 12 oz of the strained horseradish. Set aside.
Whip heavy cream in mixer on high until stiff.
Add salt, white pepper, Tabasco, mustard and horseradish and fold into whipped cream using a rubber spatula.
Place in plastic bowl and refrigerate until served. Grill tenderloin, slice, and serve on rolls topped with Morton's whipped horseradish.
NOTE: Whipped Horseradish should be made fresh the day it is served.Makes 4 Source: