Simmer balsamic vinegar until it has reduced by 2/3rds. Add honey, stir until thoroughly mixed. Then add butter, 1 T at a time, and mix until dissolved and velvety before adding the next tablespoon of butter.
While you are making the sauce. Grill the chicken and asparagus . I use a cast iron grill on my stove top. Could definitely use your outdoor grill too.
Spray chicken with a garlic olive oil and top with a sprinkle of Herbs de Provence on each piece. Grill until cooked thoroughly.
Grill the asparagus. Also spray with the garlic olive oil and sprinkle with Herbs de Provence. I also added a tiny bit of salt and pepper to both the chicken and the asparagus. This doesn't take long - about 4-5 minutes.
To plate the dish -
Drizzle about a tablespoon of sauce on the plate. Top with chicken and asparagus. Drizzle the top the dish with extra sauce. Add cracked pepper.