Melt butter in skillet. Add onion and celery and saute until tender. Stir in mushrooms and parsley. Combine seasonings and sprinkle over bread cubes. Add eggs, bouillon and onion mixture. Toss thoroughly until well combined. Spoon lightly into slow cooker. Cover and set on high for 1 hour, then reduce to low and cook for 1 to 2 hours.

Note: 22 bread slices (24 ounce loaf) cubed and toasted for 15 minutes in a 300 degree oven to make toasted bread cubes.