Whisk together the marinade ingredients in a large bowl (or use a blender). Add the chicken and mix to coat evenly.

Cover and refrigerate. Marinate at least 1 hour, or up to 4 hours for more flavor penetration.

Heat 1 tablespoon oil in a large pan over medium heat. Add the chicken and cook 4-5 minutes per side, until cooked through. You can also grill the chicken for smoky flavor.

Remove the chicken and chop into bite-sized pieces.

Rinse the rice under cold water until the water turns clear. Drain.

Melt the butter in a large pot over medium heat. Add cumin, oregano, turmeric, and salt. Stir and cook for 1 minute to bloom the spices.

Add the rice and stir to coat with the spices.

Add the chicken broth and bring to a boil.

Reduce heat, cover, and simmer for 15 minutes.

Remove from heat and rest for 5 minutes. Fluff with a fork and adjust for salt.

Add the yogurt (or sour cream), mayonnaise, vinegar, lemon juice, garlic, parsley, pepper, salt, and optional sugar to a mixing bowl. Whisk until very smooth.

Taste and adjust. If the sauce is too thick, whisk in 1-2 teaspoons water (or vinegar lemon per your taste) to achieve your desired consistency.

Reheat the chicken if needed in a pan with a bit of butter or oil and a splash of lemon juice to freshen and moisten it up.

Distribute the chicken to plates accompanied by rice, lettuce, tomatoes, and pita bread. Drizzle with halal white sauce. Serve with sriracha on the side.