Cut the chicken breasts into bit sized pieces and season with the salt, garlic powder and black pepper.
Heat oil in a large oven safe skillet over medium heat. Add seasoned chicken to the hot skillet and sear on all sides - leave in pan for about 4 minutes then remove from pan.
Reduce heat to low, melt butter in skillet and add the orzo. Toss to coat in the butter and toast for 2 minutes.
Increase heat to medium and add chicken broth, parmesan cheese, lemon juice and lemon zest to skillet. Mix until cheese is melted. Mix in the spinach and keep mixing until mostly wilted.
Mix chicken back into skillet and place in the oven to bake covered at 400F for 12-15 minutes. Check to make sure the orzo is tender and remove from oven.