IN A SAUCEPAN 
Thaw the soup in its packaging in warm water. 
Place in a saucepan and heat over medium-low heat until boiling. IMPORTANT: Do not simmer for more than a minute to retain the original amount of broth.  
Stir occasionally during cooking. 
IN THE MICROWAVE 
Remove frozen soup from its packaging. 
Place in a microwave-safe bowl. Cook for 5 to 7 minutes at maximum temperature. 
Stir 2-3 times during cooking. 
For a large amount, add a few minutes to the cooking. 
Preferably, warm the bowls before serving.