Cook potatoes in salt water. Drain and mash. Add butter, sour cream, cream cheese and cream or milk, if necessary. Place in a buttered casserole bowl and refrigerate. Bake 45 minutes at 350 degrees.
Combine eggs with milk. Add remaining ingredients except cereal and butter. Pour into a 10x6x2-inch baking dish. Combine slightly crushed cereal and butter. Sprinkle over top. Bake at 350 degrees for about 50 minutes.
Melt butter and saute onion, celery, parsley and mushrooms. Pour over bread cubes. Add all seasonings and toss well. Pour enough broth to moisten. Add eggs, mix well. Pack lightly in crock pot. Cover. Cook on high 45 minutes. Reduce to low 4-8 hours.