In a small bowl, combine olive oil, both mustards, thyme, rosemary, lemon zest, salt, and pepper. Whisk and set aside.
3. Step
Cut four sheets of foil, about 14 inches (35 cm) long.
4. Step
Divide potatoes and carrots into 4 equal portions and add to the center of each foil.
5. Step
Drizzle with olive oil and season with salt and pepper.
6. Step
Top each packet with the chicken. Using your fingers or a brush, work the mustard mixture onto the chicken. Top with lemon slices and fresh rosemary.
7. Step
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 and carrots are tender, about 30 minutes. Cooking time may take longer depending on the thickness of the breast.
