01 - Preheat your oven to 400°F (200°C). Thoroughly scrub the potatoes, pat them dry, and pierce each one several times with a fork. Rub the potatoes with olive oil and season evenly with kosher salt.
02 - Place the prepared potatoes directly onto the oven rack. Bake for 55 to 60 minutes, or until they are tender when pierced with a fork.
03 - While the potatoes are baking, prepare the filling. In a large mixing bowl, combine the shredded chicken, crumbled bacon, shredded cheddar cheese, shredded mozzarella cheese, ranch dressing, sour cream, chopped chives, and black pepper. Mix thoroughly until all ingredients are well incorporated.
04 - Once the potatoes are cool enough to handle, carefully slice each one lengthwise. Gently scoop out most of the starchy interior into the bowl with the filling, ensuring to leave about a 1/4-inch border of potato flesh intact to maintain the shell.
05 - Add the scooped-out potato flesh to the filling mixture. Mash everything together until the mixture is well combined and achieves a creamy consistency.
06 - Spoon the prepared filling back into the hollowed-out potato shells, mounding it generously. Arrange the stuffed potatoes on a baking sheet lined with parchment paper.
07 - If desired, top each stuffed potato with additional shredded cheese and bacon bits. Return the baking sheet to the oven and bake for an additional 10 to 12 minutes, or until the cheese is fully melted and the tops are golden brown.
08 - Garnish the stuffed potatoes with fresh chives. Serve hot.