Place each chicken breast-half between 2 pieces of plastic wrap and pound out to 1/4-in. thick with a meat mallet.
Combine the parsley, Parmesan cheese, 2 Tbsp. olive oil and black pepper in a medium bowl.
Lay out each chicken breast flat on a work surface. Top each breast with a slice of Prosciutto. Spread 1 Tbsp. of the parsley mixture over the Prosciutto. Roll up each chicken breast beginning with one of the narrow ends and secure with a tooth pick or kitchen twine.
Preheat a 3-qt. nonstick sauté pan on medium heat. When the rim of the pan is hot to the touch, add 2 tsp. olive oil. Swirl the pan spreading the oil over the surface of the pan. Allow the oil to heat for a minute.
Place the chicken breast rolls into the pan and brown on all sides. Remove the chicken from the pan. Deglaze the pan by adding the chicken stock and wine.
Add the carrots, leeks and onions. Place the chicken breasts on the vegetables, cover and simmer for approximately 25 minutes.
Remove the chicken rolls from the pan and place on a cutting board. Cut across each roll creating 1/2-in. slices. Divide the vegetables into 4 portions. Place a serving of vegetables and the slices of one chicken on each plate and serve.