Cream of Tomato Soup

Name: Cream of Tomato Soup
Prep time: 15 min
Cook time: 60 min
Total time: 75 min
Ingredients: 2 tbsp Butter; 1 Onion (thinly sliced); 2.25 pounds Plum Tomatoes (peeled, seeded, and sliced); 2 Potato (diced); 2 cups Heavy Cream (scant); Salt And Pepper; Parmesan Cheese (freshly grated to serve)