I burned the tortilla with my trusted Steinel 1502 heat gun.  Although this thing is capable of generating over 1000°F, I rarely use that setting.  I set it to the middle setting, which generates 800ºF.  The higher temperature tends to just scorch the tortilla, while the lower temp gives me more control over what gets burned and how deeply.

 By now I have finished my second G&T, and am on my third.