First, marinade your chicken breast in 1/2 cup dijon, 1/4 cup honey, 1 tbsp oil, garlic, salt and pepper. Let marinade in the fridge for at least 1 hour (I usually let it marinade for 2-3 hours) DO NOT skip this step, or else the chicken will not have as much flavor.
Preheat your oven to 375 degrees F.
In a mixing bowl, combine your halved brussel sprouts, 2 tbsp dijon, 1 tbsp honey, 1 tbsp olive, salt and pepper. Mix so that all the brussel sprouts are coated.
Place chicken breast and brussel sprouts on opposite sides of your pan, make sure your brussel sprouts are in a single layer. Lay the sprigs of rosemary spread out on the pan.
Bake for 35-40 minutes, or until the chicken is cooked through.
Serve and enjoy!