Slice chicken breast into thin small strips. Toss chicken in salt, pepper, garlic powder, and smoked paprika. Heat oil over medium heat. When the oil is hot, add the chicken to the pan.
Saute chicken for 7 minutes tossing frequently. While the chicken cooks, melt butter and hot sauce together. Add butter and hot sauce mixture to the pan after 7 minutes and cook for another 2 minutes. Remove the chicken from the heat.
While the chicken cools, prepare the Greek yogurt ranch dressing by mixing the yogurt, mayo, lemon juice, onion powder, garlic powder, dried dill and dried parsley in a small bowl until a smooth, even mixture remains.
Chop romaine into thin shreds and cube celery, cucumber, and avocado. Plate the romaine with the buffalo chicken, cucumber, celery, and avocado. Top with chopped scallions and the ranch dressing.