Prep the chicken. Pat the chicken dry, then season with 1/2 teaspoon salt, 1/4 teaspoon pepper, and the paprika. Dry chicken sears better and builds flavor.
Sear in a hot skillet. Heat oil over medium-high in a large skillet. Add the chicken in a single layer and cook 3–4 minutes per side until browned and just cooked through.
Remove to a plate and tent loosely.
Build the flavor base. Lower heat to medium. Add butter to the skillet. Stir in garlic and onion powder and cook 30 seconds, just until fragrant.
If using mushrooms, add now and sauté until they give up their moisture.
Deglaze with broth. Pour in the chicken broth and scrape up the browned bits. Simmer 2 minutes to reduce slightly.
Make it creamy. Whisk in the heavy cream and cream cheese. Stir until smooth and gently bubbling.
Add dried dill, dried parsley, dried chives (if using), remaining salt, and pepper. Simmer 2–3 minutes to thicken.
Optional cheesy boost. Stir in Parmesan until melted for a deeper, savory note. Taste and adjust seasoning.
Return the chicken. Add the chicken and any juices back to the skillet, turning to coat.
If adding spinach, fold it in now until just wilted.
Brighten and finish. Stir in lemon juice to balance the richness. Let everything simmer 1 more minute, then remove from heat. Garnish with fresh parsley or chives.
Serve. Spoon over cauliflower rice, mashed cauliflower, zucchini noodles, or keep it simple with roasted asparagus.
The sauce is the star—don’t waste a drop.