Preheat your oven to 375°F (190°C). Lightly grease a baking dish with olive oil or nonstick spray.
If the chicken breasts are thick, slice them horizontally to create thinner cutlets. This helps them cook more evenly and quickly. Season both sides with salt and pepper.
In a small bowl, whisk together the Dijon mustard, honey, minced garlic, olive oil, and thyme. Taste and adjust seasoning if needed.
Place the chicken breasts in the prepared baking dish. Pour the glaze over the top and use a spoon or brush to coat each piece evenly.
Bake uncovered for 25–30 minutes, or until the chicken is cooked through (internal temperature should reach 165°F or 74°C). Baste with the glaze once or twice during baking.
For extra caramelization, switch to the broiler for the last 2–3 minutes. Watch carefully to avoid burning.
Let the chicken rest for 5 minutes before slicing. Garnish with fresh thyme or lemon slices, and serve with your favorite side dishes.