Tomato-Basil Parmesan Soup

This soup is FANTASTIC. It comes out of the most recent BYU Alumni magazine and received 5 stars.

Makes about 2 quarts

2 (14 oz) cans diced tomatoes, with juice
1 cup finely diced celery
1 cup finely diced carrots
4 cups chicken broth
1 cup finely diced onions
1/2 bay leaf
1 t. dried oregano or 1 T. fresh oregano
1 T. dried basil or 1/4 cup fresh basil
1/2 cup butter
1/2 cup flour
1 cup Parmesan cheese
2 cups half and half, warmed
1 t. salt
1/4 t. black pepper

In a large slow cooker, combine tomatoes, celery, carrots, chicken broth, onions, bay leaf, oregano, and basil (if using fresh oregano and basil; if using dried oregano and basil add those two ingredients in the last hour of cook time). Cover and cook on low for 5 to 7 hours, until flavors are blended and vegetables are soft.
About an hour before serving prepare a roux: Melt butter over low heat in a skillet and add flour; stir constantly with a whisk for 5 to 7 minutes. Slowly stir in 1 cup hot soup from the slow cooker. Add another 3 cups soup and stir until smooth.
Add all back into the slow cooker. Stir and add Parmesan cheese, warmed half and half, salt, and pepper. Cover and cook on low for another hour until ready to serve.

(Note to Melynie:  1 1/2 times this recipe to fill crockpot)