Preheat oven to 375 degrees.
Prepare chicken by pounding to 1-inch thick and cutting into 4-5 ounce portions.
Whisk mustard, honey, oil, Worcestershire, thyme, garlic, salt, pepper, and paprika in a large bowl until smooth.
Reserve 2 tablespoons of the honey mustard sauce.
Place chicken into the bowl with the sauce. Toss until chicken is well coated.
Marinate chicken in the refrigerator for at least 20 minutes, or up to overnight. (You can transfer it to a gallon-sized Ziploc bag for easier storage.)
Place chicken breasts in a 9-inch square baking dish that has been lightly coated with non-stick cooking spray.
Bake chicken in preheated oven for 20-25 minutes, or until the internal temperature reaches 160 degrees. (It will increase by 5-10 degrees once removed from the oven reaching a final temperature of 165 degrees.)
Brush chicken with reserved honey mustard sauce.
Serve with a sprig of fresh thyme and enjoy.