Preheat the oven to 400°F (200°C).
Wash and pierce the sweet potatoes with a fork. Bake for 45-60 minutes until tender.
Let the sweet potatoes cool slightly, then cut them in half lengthwise and scoop out some flesh, leaving about 1/4-inch border.
Mix the shredded chicken with BBQ sauce in a bowl until well combined.
Fill each sweet potato skin with the BBQ chicken mixture, then top with shredded cheese.
Place the filled skins on a baking sheet and bake for an additional 15-20 minutes until the cheese is melted and bubbly.
Remove from the oven and sprinkle with chopped green onions before serving.