Season both sides of the chicken breasts with salt and pepper.
Heat olive oil in a large skillet over medium-high heat. Add the chicken breasts and cook until golden brown on both sides, about 4-5 minutes per side. Remove the chicken from the skillet and set aside.
In the same skillet, add minced garlic and cook for 1 minute, stirring constantly. Add the chicken broth and lemon juice, scraping the bottom of the skillet to deglaze and release any browned bits.
Bring the mixture to a boil, then reduce heat to low and simmer for 5 minutes. Add the heavy cream, butter, lemon zest, and thyme, stirring until the butter is melted and the sauce is well combined.
Return the chicken to the skillet, cover, and cook for 10-12 minutes or until the chicken is cooked through and reaches an internal temperature of 165°F (74°C).
Sprinkle with chopped parsley and serve with your favorite keto-friendly vegetables or a side salad.