I made this tonight. It is something else! I don't know who created it... but it is really good. Such simple ingredients can pack a ton of flavor. I think by using the double boiler method helps it a lot. It almost makes a 'buttermilk' flavor by using the cream and lemon juice in the butter. I was kinda not paying attention to the "serving instructions" (although the recipe "ingredients" that I made the sauce with were exact, including the grated radish), but I wrongly read step #6 and thought it said to serve it with "fried RADISHES". Since I had plenty of radishes left over, I sliced some and fried them up in EVOO with salt & pepper to use the sauce with! (Yes... I'm a dork!) Either way, it was great. Thank you for posting. (Next time I will try it with "fried DISHES"). Made for PRMR.