Add butter to a soup pot and melt over medium heat.

Add the chopped onion and diced carrot and sauté until the onions become translucent.

Add the strained tomatoes, stock, herbs and seasonings.
Simmer for 30 minutes.

Use an immersion blender to blend all of the vegetables into a creamy consistency. This can also be done in a food processor, being careful while working with the hot soup. 

Serve with a swirl of heavy cream, if desired, along with a grilled cheese sandwich for a perfect meal.