Prepare the French green beans by microwaving them in a covered bowl with a splash of water for 8-10 minutes until bright green and slightly tender. Drain and set aside.

In a large skillet over medium-high heat, melt olive oil and butter. Season the chicken thighs with salt and lemon pepper, cooking for about 4 minutes per side until browned. Remove chicken and let rest.

In the same skillet, add minced garlic and onion powder, sautéing for about 1 minute until fragrant. Stir in the cooked green beans and sliced mushrooms, cooking for 4-5 minutes until mushrooms are tender.

Pour in chicken broth and heavy cream, stirring to combine. Bring to a gentle simmer and cook for 3-4 minutes until the sauce thickens slightly.

Reduce heat to low and stir in grated Parmesan cheese until smooth. Adjust seasoning with salt or lemon pepper.

Return the browned chicken to the skillet and spoon cream sauce over it. Simmer for an additional 2-3 minutes, then serve with a garnish of fresh parsley.