It is Friday again and that means it is another chance for me to try to invent a healthier burger. This week we actually wanted a beef burger so I wanted to try to get it low fat but still moist and tasty. I had the idea of a horseradish and mushroom burger and this is what came out of those thoughts. The mushrooms are used sort of in place of breadcrumbs and their high moisture content helps to keep things moist. I think I may have thought that the horseradish would have been a stronger taste but in reality it was rather mellow but nice. If you want more of a bite from the horseradish I would suggest spreading a bit of the horseradish sauce on your burger bun as much more in the mix might make it too moist to hold up. Cooking time includes the chilling time.