As is almost always the case with the F&W website, the missing items are contained in a cross-recipe that is hyperlinked, but not at all visible as being a hyperlink. In this case, the glazed salmon listing in the ingredients is the invisible hyperlink.
Ignore my ranking. I have not made this, though it sounds like it would be good.
So my comment below is that there is no mention in the ingredient list of a horseradish glaze. Moreover, near the end it says to add the "remaining horseradish glaze", implying that there was a previous step involving this ingredient which I also don't see. I'll use this as a guide to maybe add creamy horseradish sauce to my dish which resembles this one: I'm using wild-cooked salmon I have leftover and gratinee potatoes I made for dinner the night before and I'm going to add onions, bacon and apples sauteed together, throw in the salmon in big chunks near the end, warm up the potatoes and put them at the bottom of the plate, put this mess together on top, and maybe add a fried egg. then possibly harissa or horseradish. will let you know how it goes. Sounds yum!