Coat the chicken in the spice mix (oregano, garlic powder, cumin, paprika, salt, and pepper) and rub well.
In a frying pan, heat the olive oil over medium heat and cook the chicken for approximately 3 minutes on each side. Remove the chicken from the pan and set it aside.
In the same pan, add the red and green peppers and onion, sauté for about 4 minutes.
Add the basmati rice to the pan along with the spices (salt, paprika, cumin, and turmeric). Toast for 2 minutes.
Pour in the water, cover the pan, and let it simmer for 8-10 minutes until the rice is cooked.
For the sauce, add all the sauce ingredients (Greek yogurt, mayonnaise, garlic cloves, cilantro, salt & pepper, and lemon juice) to a blender and blend until smooth.
Serve the spiced chicken over the vegetable rice and drizzle with the creamy sauce.