Icing Radicchio

I've wanted to grill radicchio for a while--it always sounds so good. I thought it would be a healthy side to the hamburgers and corn I'd thrown on the grill.

Unfortunately, I didn't read any recipes on how to cook it, so I didn't soak it in ice water first. Lordy, was it BITTER!

Next time this veggie is on sale (I think I dropped about $4.50 for a head that I tossed in the compost since it was inedible), I'll try Michael Chiraello's version.