|English: Lava rocks along Nagisa Lava Trail on Sakurajima Polski: Głazy z zastygłej lawy wzdłuż trasy Nagisa na Sakurajimie (Photo credit: Wikipedia)|
"This tip comes from Top Chef vet Preeti Mistry, talking to the folks at Chow.com. You'll need some expandable grill grates that are easy to remove and replace (if your grill doesn't have them already) and enough lava rocks to form a tightly packed layer around the gas burners.
Layer in the lava rocks, cover them over with the grates, and fire up the grill. Wait about 20 minutes or so, and your grill will be ready to go: just be careful when you open the lid, it'll be seriously hot in there."