Preheat oven to 400 degrees F.
On a large baking sheet, toss together the onion, bell pepper, garlic, potatoes, artichoke heart, tomatoes and capers with 2 tablespoons olive oil, 1 teaspoon salt, 1 teaspoon black pepper, red pepper flakes, and half of the oregano until evenly combined. Shake the pan so that everything is in a single layer.
Place the chicken things on top of the veggies, spacing them out evenly on the baking sheet. Drizzle the chicken with the remaining olive oil and season with the remaining salt, pepper and oregano.
Roast until the chicken has begun to brown on top, and the veggies have softened, about 30 minutes. Remove the pan from the oven and sprinkle with kalamata olives. Return the chicken to the oven and continue to cook for 10 minutes longer. The chicken should register 165 degrees F with a thermometer. Remove the pan from the oven let the chicken rest for about 5 to 10 minutes before serving. Garnish with fresh lemon juice, feta and parsley. Enjoy!