Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
Chop the chicken breast into bite-sized cubes and dice the red potato into 1/2-inch pieces.
Slice the carrots into 1/4-inch thick rounds.
In a large mixing bowl, combine the chicken, potatoes, and carrots. Drizzle with olive oil and sprinkle with dried oregano, garlic powder, sea salt, and black pepper.
Toss the mixture thoroughly until every piece is evenly coated in oil and spices.
Spread the ingredients in a single layer on the prepared baking sheet, ensuring they are not overcrowded so they roast rather than steam.
Roast in the oven for 20-25 minutes, or until the chicken is cooked through and the vegetables are tender and golden brown.
Remove the sheet from the oven and immediately sprinkle the crumbled feta cheese over the hot chicken and vegetables.
Garnish with freshly chopped parsley and serve immediately while the feta is slightly softened.