1. Preheat your oven to 400 F (200 C). Wash the sweet potatoes thoroughly under cold running water, scrubbing off any dirt. Pat them completely dry with a paper towel. Using a fork, pierce each sweet potato several times all over. This allows steam to escape during baking and prevents them from bursting.

2. Lightly rub each pierced sweet potato with olive oil, then sprinkle with a pinch of salt and pepper. Place the sweet potatoes directly on an oven rack or on a baking sheet lined with parchment paper. Bake for 40-50 minutes, or until they are very tender when squeezed gently and easily pierced with a fork. The exact time will depend on the size of your potatoes.

3. While the sweet potatoes are baking, combine the shredded cooked chicken and BBQ sauce in a medium saucepan. Heat over medium-low heat, stirring occasionally, until the chicken is thoroughly heated through and coated evenly with the sauce, about 5-7 minutes. If the mixture seems too thick, you can add a tablespoon or two of water or chicken broth.

4. Finely chop the red onion and fresh cilantro. If you plan to use other toppings like green onions or cheese, get those ready now as well. Having everything prepped before the potatoes are done makes assembly quick and easy.

5. Once the sweet potatoes are cooked, carefully remove them from the oven. Using a sharp knife, make a lengthwise slit down the center of each sweet potato, being careful not to cut all the way through to the bottom. Gently squeeze the ends of the potato inward to open it up and fluff the flesh with a fork.

6. Spoon a generous amount of the warm BBQ chicken mixture into each opened sweet potato. Top with the chopped red onion and fresh cilantro. Add any other desired toppings like a dollop of sour cream or a sprinkle of shredded cheese. Serve immediately and enjoy your delicious, comforting meal!