The solution is to replace the old lava rocks with these grilling tiles made of a special cordierite ceramic that distributes heat uniformly. Their shape allows them to catch drippings, reducing flare-ups. They are even self-cleaning, as they can be simply flipped over to burn off any residue.
The 2"x3-1/2" tiles come in packages of 30 (210 sq.in.) or 45 (315 sq.in.).
Made in USA.