I use flax oil, so, all seasoning is done on the weber outside. Hang an oven thermometer on the warming rack to learn what settings the burners should be on to get the temp you want. ALWAYS check it before seasoning, ambient temps affect the interior temps of an outdoor grill because most are not insulated. My grill has 3 burners, front to back, I put the CI upside down toward the rear, front burner on high, the other 2 burners on low, or, adjusted to get 450F. Do NOT trust your built in grill thermometer unless you have tested it. It lives outdoors and most of them are not accurate to begin with.