Pound the chicken breasts to an even thickness and season both sides with Italian seasoning, garlic powder, and salt.
Heat the olive oil in a large skillet over medium heat. Add the chicken and cook for 5–6 minutes per side, or until golden and cooked through. Transfer to a plate and cover loosely with foil.
In the same skillet, add chicken broth, lemon juice, and lemon zest. Stir to scrape up any browned bits from the bottom of the pan. Simmer for 1–2 minutes.
Reduce heat to low. Whisk in the sour cream and butter until smooth and creamy.
Return the chicken to the pan and spoon the sauce over the top. Simmer for 2–3 more minutes until heated through.
Pound the chicken: Flattening the chicken breasts ensures they cook evenly and stay juicy.
Use fresh lemon: Bottled lemon juice works in a pinch, but fresh juice and zest give the best flavor.
Don’t boil the sour cream: Keep the heat low when adding the sour cream to prevent curdling. Whisk it in gently for a smooth sauce.
Deglaze for flavor: Scrape the bottom of the pan after adding broth and lemon juice, this pulls in all the flavorful browned bits from searing the chicken.
Adjust the consistency: If the sauce is too thick, add a splash of broth. If it’s too thin, let it simmer uncovered for another minute or two to reduce.
Add-ins: For a twist, stir in a handful of spinach or a few spoonfuls of capers just before serving.