Vegetable Chicken Soup

I am kind of laughing to myself as I post this recipe...it's supposed to be near 100 degrees on Tuesday.  I doubt seriously that I will be making soup anytime soon but I also know that the seasons change here in the Chicago area.  Sometimes twice in a day!  In all seriousness...I will probably start working on this recipe towards the end of Summer to take advantage of some fresh vegetables from the farmer's markets I go to.  Perhaps I will rename this recipe farmer's market soup.

1 large sweet onion, chopped
1 C. thinly sliced baby portobello mushrooms
1/2 C. chopped green pepper
1/2 C. chopped sweet red pepper
5 garlic cloves, minced
1 tbsp. butter
1 tbsp. olive oil
3/4lb. boneless skinless chicken breasts, cut into half inch cubes
49oz. chicken broth
1 28oz. can crushed tomatoes, undrained
2 medium carrots, cut into 1/4 inch slices
1/2 C. pearl barley
1 3/4 tsp. Italian seasoning
1 1/2 tsp. pepper
1/2 tsp. salt

In a large skillet, saute the onion, mushrooms, green and red peppers and garlic in butter until tender.  Transfer to a 5qt. slow cooker.  Add the remaining ingredients.  Cover and cook on low or until chicken and barley are tender.