Season chicken breasts with salt and pepper on both sides.
In a small bowl, mix balsamic vinegar, honey, Dijon mustard, and thyme. Set aside.
Heat olive oil in a large skillet over medium-high heat.
Add chicken breasts and cook for 5–6 minutes per side, or until golden and almost cooked through.
Lower the heat to medium, add minced garlic, and sauté for 30 seconds until fragrant.
Pour the balsamic glaze mixture over the chicken.
Simmer for 5–7 minutes, occasionally spooning glaze over chicken, until the sauce thickens and chicken is fully cooked (internal temp 165°F / 74°C).
Remove from heat. Let rest for 2 minutes.
Serve with the glaze spooned over the top and garnish as desired.