01 - Preheat oven to 425°F (220°C). Lightly grease a 9x13-inch baking dish.
02 - Combine potato cubes with 2 tablespoons olive oil, salt, black pepper, and smoked paprika in a large bowl. Toss to coat evenly.
03 - Spread seasoned potatoes in the prepared baking dish. Roast for 20 minutes, stirring halfway through for even browning.
04 - While potatoes roast, toss chicken cubes with 1 tablespoon olive oil and Cajun seasoning in a separate bowl until thoroughly coated.
05 - Remove potatoes from the oven after 20 minutes. Scatter Cajun-seasoned chicken evenly over the roasted potatoes.
06 - Return baking dish to the oven and bake for an additional 20 minutes, until chicken is fully cooked and potatoes are golden and tender.
07 - Sprinkle shredded cheddar cheese and crumbled bacon over the hot casserole. Return to oven for 3–5 minutes, until cheese is melted.
08 - Remove from oven. Top with chopped green onions and dollops of sour cream. Serve hot.