Trim the ends of the French green beans and set aside.
In a large skillet, heat olive oil and butter over medium-high heat.
Add sliced chicken breasts to the skillet, season with salt and lemon pepper, and cook for about 4 minutes on each side until browned and cooked through. Remove chicken from the skillet and set aside.
In the same skillet, add minced garlic and onion powder, then add the green beans and mushrooms. Cook for 4-5 minutes until the vegetables are tender-crisp.
Pour in chicken broth and heavy cream, and simmer for a couple of minutes until the sauce slightly thickens.
Stir in grated Parmesan cheese until melted and well combined.
Return the cooked chicken to the skillet and toss to coat with the sauce. Cook for an additional 2-3 minutes until everything is heated through.
Serve warm, garnished with additional Parmesan cheese if desired. Enjoy your Green Bean Chicken Skillet!