Things the peppers: Cut off the stem end of the peppers. Scrap out the seeds and ribs utilizing a little determining spoon. Toss the cheese, ancho pepper, garlic powder, and cumin in a medium bowl until the spices are equally dispersed. Load the peppers with cheese, overrunning them somewhat, setting each pepper in the pepper rack as you finish it.
Set the grill up for indirect high heat: Set the grill up for a two-zone fire, with one zone set to high heat, and the other without any heat. I pre-heat the grill with all burners on high for 15 minutes, brush the grill grates clean, then switch off all burners except for burners # 1 and # 2.
Grill-roast the peppers over indirect heat for 20 minutes: Put the rack of peppers on the grill over indirect heat, not directly over the flames. Close the cover and grill until the cheese melts and browns, and the peppers soften after about 20 minutes.
Serve: Remove the rack from the grill. (Be mindful, and secure your hands-- the rack is extremely hot.) Set the rack on a heat-safe surface and let the packed peppers cool for five minutes, then eliminate them from the rack and serve.