Prep the chicken and beans: Pat chicken dry and season with salt, pepper, and 1 tablespoon ranch seasoning.
Trim green beans and set aside.
Sear the chicken: Heat olive oil in a large skillet over medium-high. Add chicken in a single layer and sear 3–4 minutes per side until browned and cooked through. Transfer to a plate and keep warm.
Sauté the beans: Reduce heat to medium.
Add butter to the same skillet. Toss in green beans with a pinch of salt and cook 4–6 minutes, stirring occasionally, until crisp-tender and lightly blistered.
Add aromatics: Stir in garlic for 30 seconds until fragrant. Don’t let it burn.
Build the sauce: Pour in chicken broth and scrape up any browned bits.
Whisk in cream cheese until smooth, then add heavy cream, remaining 1 tablespoon ranch seasoning, and Parmesan. Simmer 2–3 minutes to thicken.
Return the chicken: Add chicken back to the pan, along with any juices. Stir to coat everything in the sauce.
Simmer another 1–2 minutes. Adjust salt and pepper. Add lemon juice if using.
Finish and serve: Sprinkle with red pepper flakes and fresh herbs.
Serve hot, spooning extra sauce over the top.