I grilled it long enough to get grill marks, flipped it over and did the same on the other side. Then I lowered the heat and let it cook a bit. It is still crunchy but not quite raw. I brushed olive oil on before grilling and sprinkled with salt and pepper. This all resulted in me eating almost an entire head of cauliflower by myself. Yikes.
Thanks! Some day it will be warm enough to grill here again.