Put tomatoes, celery, carrots, onions, chicken broth, oregano, basil and bay eaf in slow cooker.

Cover and cook on low for 5 - 7 hours.

30 minutes before serving prepare a roux. Melt butter over low heat in a skillet and add flour. Stir constantly with a whisk for 5 - 7 minutes. Slowly stir in 1 cup soup. Add another 3 cups hot soup and stir until smooth. Add all back into the slw cooker.

Stir and add the parmesn cheese, warm half and half, salt and pepper.

Add addition basil and oregano as needed.

Cover and cook over low for 30 minutes.