1. Toast bread cubes and set aside for later use.
2. Melt margarine or butter in medium size fry pan.
3. Add celery and onion; cook until tender, about 10 minutes.
4. Add parsley, mushrooms, seasoning and broth. Cook for 5 minutes.
5. Remove from heat and add the toasted bread cubes. Cover and let stand 10 minutes. Serve immediately.
6. Refrigerate leftovers within 2 hours.