I once made a tuna marinade that included some imitation wasabi paste. Usually when I cook like this, once the fish is done I cook down the marinade into a thicker sauce. In this case, the sauce quickly clumps when heated into a goop with a similar appearance and texture of cooked chicken fat. Obviously then I can't use it, so since then I just throw out this marinade since I can't use it without heating it (it had the raw fish in it.)
Why does horseradish do this? I'm assuming that's the culprit ingredient since it's the only unusual thing that I don't have in others that don't have this problem. And in any case, is there something I can do about it, or do I just have to throw this one away?