Start by patting the chicken breasts dry with a paper towel. Season both sides evenly with salt, pepper, and garlic powder. This step ensures the chicken is flavorful all the way through and helps it brown nicely in the pan.
Heat olive oil in a large skillet over medium heat. Add the seasoned chicken breasts and cook for about 5–6 minutes per side until golden brown. Remove the chicken from the skillet and set it aside on a plate.
In the same skillet, melt the butter over medium heat. Add the minced garlic and sauté for about 30 seconds until fragrant. Be careful not to burn it, as burnt garlic can turn bitter.
Stir in the Dijon mustard, chicken broth, heavy cream, and dried thyme. Use a spoon to scrape up any browned bits from the bottom of the pan, as these add incredible flavor. Let the sauce simmer gently for 3–5 minutes until slightly thickened.
Place the seared chicken breasts back into the skillet, nestling them into the sauce. Spoon some sauce over the top of the chicken to coat it well. Reduce the heat to low and simmer for 8–10 minutes until the chicken is fully cooked.
Once the chicken is tender and the sauce has thickened, remove the skillet from heat. Taste and adjust seasoning if needed. Sprinkle with fresh parsley before serving for a pop of color and freshness.