Saute onion, celery, carrot, leek in olive oil until very well colored. Add half the thyme, bay leaf, pepper, and stock. Bring to a boil. Simmer for 1 hour. Strain stock into another pan. Add remaining thyme, garlic, and salt to stock. Bring to a boil. Simmer for 15 minutes. Lift out the thyme and add cream to the soup. Heat gently. Serve with garlic bread.