When I saw this the other day I just had to make it ASAP!
Then I googled it and there are several versions - so all you have to do is use your usual guacamole recipe - then grill the ingredients. (Leave the skin on the avocado or it will be mushy.) Grill until you get some great grill marks but veggies are not too soft. Let cool and then chop/mash into bowl. Eat immediately or chill if you prefer. You can even freeze for later if you make too much :)
I freeze in 1/2 cup containers. Fill as much as possible so the air doesn't get in there and turn it brown. Defrost in the refrigerator.
It looks a little brighter than "raw" guac does. And my limited camera skills make it even greener!