Slice Italian sausages.

Dice celery and onion.

Thinly slice zucchini.

In a large saucepan, brown sausages. If using turkey sausage, spray pan with vegetable spray first.

Pour off any excess fat.

Add celery, zucchini, and onion to the saucepan.

Sauté for 2 minutes, stirring continuously.

In a crockery pot, combine beef stock, tomato sauce, and basil. Mix well.

Heat on HIGH (300) for 30 minutes.

Add the sausage-vegetable mixture to the crockery pot.

Turn the heat to LOW and cook for 2 to 3 hours.

Season with salt and pepper to taste.

Ladle the soup into bowls.

Garnish with grated parmesan or romano cheese.