In a small bowl, combine onion powder, paprika, salt and pepper. Season chicken pieces generously with the spice mixture. Set aside
Arrange green beans in a microwave safe dish with 1/2 cup water. Cook in the microwave for 8-10 minutes, until almost done but still crisp.
Melt 2 Tbsp butter in a large skillet over medium-low heat. Lay the seasoned chicken in one layer in the skillet. Cook for 5-6 minutes then flip and cook another 5, until cooked through and a internal temperature is 165. If the chicken browns too quickly, lower the heat. Adjust timing depending on the thickness. Transfer chicken to a plate and set aside
In the same skillet, lower the heat and melt the remaining tablespoon of butter. Add chopped parsley, garlic, hot sauce, red crushed pepper flakes, and pre-cooked green beans and cook 4 to 5 minutes, stirring regularly, until cooked to your liking. Add lemon juice and chicken stock and reduce the sauce for a few minutes , until slightly thickened.
Add cooked chicken back to the pan and reheat quickly. Adjust seasoning with pepper and serve immediately, garnished with more crushed red pepper, fresh parsley and a slice of lemon if you like.