One day last week I was cooking a roast and making a bunch of sauteed mushrooms to go along with it. I was slicing away at the mushrooms when I realized this was going to take a long time - I had two containers of mushrooms to slice.
A light bulb went off and I started searching the back of my utensil drawer. I found my egg slicer and stuck a mushroom in and pushed down the top. It worked like a charm! I finished slicing all those mushrooms in no time.