Prep the chicken: Pat the chicken dry. Slice breasts horizontally into cutlets or cube into 1-inch pieces. Season lightly with salt, pepper, and 1 tablespoon ranch seasoning.

Sear the chicken: Heat oil in a large skillet over medium-high. Add chicken in a single layer and cook 3–4 minutes per side (2–3 minutes if cubed) until browned and just cooked through. Remove to a plate and tent with foil.

Sauté the veggies: In the same skillet, add a splash more oil if needed. Add broccoli and green beans first if using, cooking 3–4 minutes to soften slightly. Add zucchini last for 2 minutes so it stays crisp-tender. Season with a pinch of salt and paprika. Transfer veggies to the plate with chicken.

Build the sauce base: Lower heat to medium. Add butter (if using) and garlic. Cook 30 seconds until fragrant. Pour in chicken broth, scraping up the browned bits. Stir in remaining ranch seasoning and red pepper flakes.

Make it creamy: Whisk in cream cheese until smooth and melty. Slowly add heavy cream, stirring until the sauce is silky. If using Parmesan, stir it in now. Simmer 2–3 minutes to thicken slightly.

Combine: Return chicken and veggies to the skillet, along with spinach. Toss gently to coat. Simmer 1–2 minutes until spinach wilts and everything is hot. Squeeze in a little lemon to brighten.

Taste and adjust: Add salt only if needed, and more pepper to taste. If the sauce is too thick, loosen with a splash of broth or cream. Too thin? Simmer another minute.

Portion for meal prep: Divide evenly into 4–5 airtight containers. Garnish with chopped chives or parsley.