In a bowl, whisk together pesto, Dijon mustard, vinegar, and wine (or chicken broth). Stir in diced tomatoes, including juices.
Place chicken in a large baking dish (about 9-inch by 13-inch) that has been sprayed with cooking spray. Sprinkle chicken with a little bit of salt and pepper, to taste.
Pour sauce over chicken and toss to make sure that each piece of chicken is well coated. Place garlic cloves and fresh herbs in the dish (tucked alongside the chicken).
Bake uncovered for 30-40 minutes, or until meat thermometer reads 165 degrees F. Remove garlic cloves and herb sprigs before serving, and be sure to spoon plenty of the delicious pan sauce over the chicken!
Notes
If you're unsure if the chicken is cooked test with a meat thermometer and make sure it reaches 165F.
You can use chicken thighs instead of breasts.
You can prep the chicken in advance and keep it in the fridge until you are ready to bake.