In a bowl, combine the greek yogurt, olive oil, lemon juice, minced garlic, oregano, paprika, garlic powder, salt, and pepper. Place the chicken in the marinade. Refrigerate 30 minutes to a few hours.
Grill, or cook in a skillet until the internal temperature reaches 165 degrees.
Preheat the oven to 400 degrees.
In a bowl, toss the potatoes with the salt, pepper, olive oil, lemon juice, garlic, and oregano. Place in a single layer on a sheet pan.
Bake for 20 minutes. Flip, and bake an additional 10 minutes.
Serve on a plate or in a bowl with the chicken and toppings.