In a bowl, whisk together flour, salt, pepper, and garlic powder. Dip chicken in, flipping to coat all sides.
Grease a large skillet and cook chicken over medium heat 5-8 minutes on each side until cooked through and lightly browned. Transfer chicken to a plate, cover with foil and set aside.
In the pan where you cooked the chicken, add pesto and saute for 1-2 minutes over medium heat until fragrant. Add heavy cream and stir until hot throughout and combined with pesto. Add salt and pepper to taste.
Add chicken to pan, sprinkle parmesan cheese on top, and cook until cheese is melted. Sprinkle with freshly chopped basil or parsley and serve hot.