Heat soup on stovetop over medium heat. Avoid boiling.
Measure out heavy cream. The general rule is 1/2 cup of cream for every eight bowls of soup, but add more or less depending on your taste.
When the soup is hot but not boiling, slowly add the cream and stir with a ladle until fully incorporated.
Scoop a spoonful of soup and cool by blowing it with your lips. Taste to ensure that you're satisfied with the flavor and consistency.
Turn off stove and pour soup into serving bowls.