Place the stock in a large saucepan and bring to a boil. Add the chicken breasts, peppercorns, bay leaf and sprig of rosemary or thyme. Reduce the heat, cover and simmer gently for 15 minutes.
Using a slotted spoon, remove the chicken from the saucepan and leave until cool enough to handle. Strain the stock and return the liquid to the saucepan.
Add the leeks, carrot and macaroni to the stock. Bring to a boil and then reduce the heat, cover and simmer gently for 15 minutes.
Meanwhile, slice the chicken breasts in small pieces and add them to the broth along with the red pepper. Simmer for 1 0 minutes more, until the vegetables are tender.
Stir in the chopped thyme and season to taste with salt and pepper.
Serve in warm soup bowls and sprinkle 1 teaspoon of parmesan cheese over each serving.
Preparation time: 10 minutes Cooking time: 40 minutes Freezing recommended