Preheat oven to 400°F. Poke holes in potatoes with a fork. Rub each potato in olive oil. Place on a baking sheet and bake for 1 hour. Remove from heat and let cool 15 to 20 minutes.

Cook ground chicken and onions in a frying pan over medium heat, stirring frequently, about 7 to 9 minutes. Stir in taco seasoning and cook for an additional 2 to 3 minutes. Remove from heat and set aside.

Cut the top of the potatoes lengthwise and carefully spoon out the inside of the potato. Save the insides to eat later, if you wish.

Fill potato shells with taco mixture, about 3 to 4 tbsp per potato. Sprinkle with cheddar cheese.

Bake at 350°F for 5 to 7 minutes, or until cheese is melted and potatoes are hot.

Garnish with sour cream, tomatoes, and green onions, if desired.