In a medium bowl, whisk together the apple cider, Dijon mustard, honey, minced garlic, thyme, salt, and pepper until well combined. Set aside.

Heat the olive oil in a large skillet over medium-high heat. Season the chicken breasts with salt and pepper, then add them to the skillet. Sear the chicken for about 5 minutes on each side, or until golden brown.

Pour the cider mixture over the chicken in the skillet, ensuring it is well coated. Bring the mixture to a simmer.

Reduce the heat to medium, cover the skillet, and let the chicken cook for about 15-20 minutes, or until the internal temperature reaches 165°F (75°C).

Remove the cover and let the sauce reduce for an additional 5-10 minutes, stirring occasionally, until it thickens and glazes the chicken.

Once cooked, transfer the chicken to a serving plate and drizzle the thickened cider glaze over the top. Garnish with additional thyme if desired.