I have had several grilled greens dishes that I find just addictive: grilled romaine, treviso, radicchio.
What is the proper technique for this? Do I blanch the greens first or just put them on the grill? Do I grill on direct or indirect heat? About how long to get that nice smokiness? I have also had very unsuccessful versions and want to avoid those mushy or charred-to-cinders results.
When I grill radicchio I just halve or quarter it and toss with EVOO and balsamic, and pepper, and grill over direct heat. Turn with tongs frequently to prevent burning. No blanching.
Yes, you definitely have to babysit it the entire time and turn it often while it's grilling so it won't burn (broiling will work also if you don't want to go outside). Romaine works well too, with a simple vinagrette and chopped cooked bacon.
A restaurant once told me that they soak the head of romaine in water (w/ vinegar in it) prior to grilling.
Then they dress it after it is cooked. It was delicious!