Rinse turkey with cold water and pat dry with a paper towel. Place on rimmed baking sheet, season generously with salt and pepper, then let sit at room temperature for 1 hr
20 min. before cooking, preheat gas grill to medium-high or light coals. Stir together cider, apple, brown sugar and soy sauce in a medium saucepan. Bring to a boil over medium-high heat. Reduce heat to medium and continue cooking, stirring occasionally
When grill is ready, turn o center burner(s) or rake coals to edges, banking them. Center steam pan below grate and pour in about 1/2" of water. Add apple and green onions to pan
Pat turkey dry with clean paper towel and season a second time. Rub avocado oil over skin. Working quickly, center breast on grate directly over prepared steam pan. Cover grill immediately
Cook until thickest part of breast registers 165° (be careful not to touch breast bone with thermometer), about 1 to 1 1/2 hrs. Add more water as needed during cooking.
15 min. before turkey is done, open grill and quickly brush on half the glaze. Cover grill and finish cooking
Transfer turkey to cutting board, tent with foil and rest for 15 min. to finish cooking and preserve juiciness
Slice and serve immediately with reserved glaze