Prepare the green beans by placing them in a microwave-safe dish with a splash of water. Cover the dish and microwave for 8-10 minutes until they are crisp-tender.

In a large skillet, heat 1 tablespoon of olive oil and 1 tablespoon of butter over medium-high heat. Once the butter begins to sizzle, add the sliced boneless skinless chicken thighs seasoned with salt and lemon pepper. Cook for about 4 minutes on each side, or until the chicken is golden brown and reaches an internal temperature of 165°F. Remove the chicken from the skillet and set it aside.

In the same skillet, add another tablespoon of butter if needed, then stir in minced garlic, onion powder, pre-cooked green beans, and sliced mushrooms. Sauté the mixture for 4-5 minutes, allowing the mushrooms to soften.

Pour in 1 cup of chicken broth and ½ cup of heavy cream into the skillet, stirring to combine. Bring the mixture to a gentle simmer, cooking for about 3-5 minutes until the sauce thickens slightly.

Once the sauce has thickened, stir in ½ cup of grated Parmesan cheese, allowing it to melt into the creamy sauce. Taste and adjust the seasoning with more salt or lemon pepper if desired.

Finally, return the cooked chicken to the skillet, allowing it to soak up the flavors of the sauce for a minute. Carefully transfer the entire dish to a serving plate and garnish with freshly chopped parsley.