Made this dish with a couple tweaks. First, the cooking time seemed waayyy too long. I grilled the steak outdoors five minutes on each side, sufficient for medium rare. That said, I ALSO let the steak rest for five or six minutes before slicing. It's surprising that the recipe does not advise you to do that. The horseradish cream adds little to this dish. I think that partially due to the sugar in the rub--the two flavors seem to compete. I might consider reducing the sugar to a half tablespoon next time to let the flavors of the cream (and the rub) be more pronounced. Lastly, I discovered this recipe too late to marinade the steak overnight. However, even with just four hours in the fridge, it imparted a very nice flavor to the meat.
This dish was fantastic on 3 levels: 1) The marinade (Bourbon: I used Makers Mark) is not overwhelming, but I was able to taste a hint of bourbon.... 2) The rub was sweet at first and spicy on the finish, and took any bite away from the bourbon. 3) It crusted up quite well under the broiler. 1 caveat: I used my oven broiler and placed it on High for 8 minutes a side. While the exterior was cooked perfectly, the flank steak came out well done, about 3 degrees off of what I wanted (Medium rare to medium, ideally). In the future, I would maybe cook on 6 minutes a side. It was my own fault for not checking the temperature of the meat throughout cooking, and the recipe didn't specify High or Low broiler setting. RECOMMEND HIGHLY!