Preheat oven to 400 degrees Fahrenheit (200 degrees Celsius).
On a large rimmed baking sheet, toss potato cubes with 1.5 tablespoons of olive oil, 0.5 teaspoon salt, and 0.5 teaspoon paprika.
Spread potatoes in a single layer and roast for 15 minutes.
While potatoes roast, in a mixing bowl, toss chicken cubes with the remaining 1.5 tablespoons olive oil, 0.5 teaspoon salt, pepper, garlic powder, oregano, and 0.5 teaspoon paprika.
Remove the baking sheet from the oven, slide potatoes to one side, and add the seasoned chicken to the other side.
Return the tray to the oven and roast for an additional 15 to 20 minutes until the chicken reaches an internal temperature of 165 degrees Fahrenheit.
During the last 2 minutes of roasting, lightly sauté spinach in a pan until wilted.
Divide the roasted chicken, potatoes, and spinach into four bowls and serve with lemon wedges.