In a small bowl whisk together Dijon mustard, maple syrup, vinegar, and garlic.
Place chicken thighs in a shallow baking dish.
Pour ¾ of the marinade over the chicken thighs.
Place extra marinade in the refrigerator.
Sprinkle rosemary and thyme leaves over chicken.
Cover chicken and refrigerate for 30 minutes or overnight.
When ready to cook chicken heat spray a griddle or grill pan with olive oil spray.
Heat the grill over medium-high heat.
Place chicken thighs on the grill pan and grill for about 5 minutes per side.
During grilling baste with extra marinade.
Marinated the thighs for at least 30 minutes. If you want to prep the recipe earlier you can marinate longer.
Use pure maple syrup, not pancake syrup.
If you don't have sherry wine vinegar (or can't find it) you can use red wine vinegar.
If you don't have fresh herbs don't buy them unless you have another recipe to use them up. You can you dried rosemary and thyme (about ½ teaspoon each) or just omit them both. The herbs are a nice touch, but I never want anyone to spend money on something that might go to waste.