Tuscany Peasant Soup

• 4 mild italian sausages
• 1 stalk celery (inner)
• 1 onion
• 700 ml beef stock
• 230 ml tomato sauce
• 1 gr basil (fresh chopped)
• 1 gr basil (dried)
• 3 slices zucchini
• some salt and pepper
• some parmesan