Preheat oven to 375 degrees F
Wash Chicken Breasts and pat dry
In a small bowl, combine 2 tablespoons olive oil, Dijon and whole-grain mustard, dried thyme, dried rosemary, and lemon zest; season with salt and pepper, to taste. Set aside.
Season halved potatoes with oil, salt, and pepper. Set aside.
Cut four sheets of foil, about 12-inches long. Divide potatoes into 4 equal portions and add to the center of each foil in a single layer.
Fold up all 4 sides of each foil packet. Drizzle with remaining 1 tablespoon olive oil and season with salt and pepper, to taste; gently toss to combine.
Top each packet with the chicken. Using your fingers or a brush, work the mustard mixture onto both sides of the chicken. Top with lemon slices.
Fold the sides of the foil over the chicken, covering completely and sealing the packets closed. Place foil packets in a single layer on a baking sheet. Place into oven and bake until the chicken is cooked through and the potatoes are tender about 25-30 minutes.*