Season the chicken and pork roast with salt and pepper. Place the meat in a large stock pot. Add the onions, carrots, and celery. Pour water ver the chicken and pork roast (about 3 to 4 quarts).

In a double piece of cheesecloth (about 4 inches by 4 inches) place 2 garlic halves, 3 bay leaves, 3 sprigs of thyme, and 1 teaspoon black peppercorns. Using a piece of twine, tie the cheesecloth closed, forming a pouch. This is called a bouquet garni. Place the garni in the stock pot and cover. Bring the liquid to a boil and reduce to a simmer. Cook until the chicken and pork are very tender, about 1 1/2 hours. Skim off any scum that has risen to the top.

Remove the chicken and pork from the pot. Pick the meat from the chicken and discard the carcass. Slice the chicken and pork meat into 1/4-inch slices. Set the meat aside. Strain and reserve the liquid. Season the reserved liquid with salt and pepper.

Using a sharp knife, cut 2 inches off the top of the melon and reserve the top. Using a spoon, scrape out the seeds of the melon and discard. Using the sharp knife, cut away as much of the melons flesh as possible, but still leaving the whole melon intact. Try to cut pieces that are about 1-inch in thickness. Cut the flesh into 1-inch pieces. Place the melon in the stock pot and cover with the reserved liquid.

Make another bouquet with the reserved garlic, bay leaves, thyme, and peppercorns. Place the garni in the melon and cover with the reserved melon top. Bring the liquid to a boil and reduce to a simmer. Simmer the liquid for about 1 hour.

Carefully remove the top of the melon and add the chicken, pork meat and reserved melon pieces, replace cover, and continue to cook for about 20 to 25 minutes, or until the melon is tender. Add the parsley. Carefully remove the melon from the pot, using two large spiders. Place the melon in a large decorative bowl. Ladle the remaining liquid from the pot into the melon and around the melon. Serve the soup hot.