Chop tomatoes into 1/2 inch pieces.  Heat olive oil in a 12 inch sauce or frying pan with tall sides.  Add onion and cook until tender.  Add tomatoes and cook for 20 minutes on medium low heat, stirring occasionally.

When tomatoes are tender, add pesto and stir until combined.  

Place half of the tomato mixture in a blender.  Mix until smooth.  While blending, pour in half of the cream.  When combined, return to a sauce pan.  Repeat with the other half of the tomatoes and cream.

Mix all of the soup and add salt and pepper to taste.  Let simmer on lowest setting until ready to eat.