Pour in the chicken broth and lemon juice, and bring the mixture to a simmer. Scrape any browned bits from the bottom of the pan.
Add the heavy cream and simmer for 2-3 minutes until the sauce begins to thicken slightly.
Reduce the heat to low and whisk in the butter, one piece at a time, until the sauce is smooth and creamy.
Stir in the lemon zest and capers (if using). Season with salt and pepper to taste.
Combine and Serve:
Return the cooked chicken to the skillet, coating it in the lemon butter sauce. Simmer for an additional minute to ensure the chicken is heated through.
Garnish with chopped fresh parsley before serving.