After all your left overs have been mixed well with the macaroni, cover and simmer on the stove until thoroughly heated about 25 mins.
Top with freshly grated Parmesan cheese.
In a large saucepan, covered with a greased round of wax paper and the lid, "sweat" the well washed leek, onion, garlic, salt and pepper in Fleischmann's Margarine.
Cook for 20 minutes, or until the vegetables are very soft.
Add potatoes, watercress and chicken stock.
Simmer for 25 minutes.
Puree the mixture through the medium disk of a food mill into a bowl and return the puree to the pan.
Add milk and cream and bring the soup to a simmer.
Add salt and pepper to taste.
Divide the soup among 6 heated bowls and garnish each serving with watercress leaves and 1 tbsp. well washed, minced and blanched leek.