Quarter the tomatoes and cut out the stem end. Then put the tomatoes on top with the water and simmer for about 15 minutes. Then rub the tomatoes through a sieve (Lotte liquor works great) and set aside.
Wash out the saucepan (or use a different one) and fry the onion, garlic and rosemary in the butter. When the onions are golden yellow, dust with flour and sweat (do not color). Now put the tomatoes back in the pot, add the cream and simmer for another 15 minutes. If the soup is not yet intense in taste, let it simmer until it has a creamy consistency.
Season to taste with salt, sugar, balsamic vinegar and pepper - if the tomato flavor is missing, then help out with tomato paste.