Season chicken thighs generously with salt and pepper.
Heat a gas grill to medium-high, 425˚F. When it reaches temperature, turn off burners in one area to create an indirect heat, cool zone. Place chicken thighs, skin side up, on the cool side of the barbecue and close the lid. Increase burners in hot zone as needed to maintain a temperature of about 425˚F.
Set a timer for 45 minutes. Check the grill occasionally to confirm that the temperature is staying around 425˚F (preferably without opening the lid). The chicken thighs are done at 45 minutes (to check for doneness, a meat thermometer should read a minimum 165˚F internal temperature). Transfer to platter and serve.
See post for infographic and explanation of two-zone grilling.
If your chicken thighs are small (lighter than 6-ounces) start checking for doneness at 35 minutes.