Put the cream of mushroom soup and cream of chicken soup into your blender. Peel your onion and cut it into wedges, add it into the blender with the soups. Add in your poultry seasoning and celery seasoning. Add in about 1/2 cup of chicken broth, enough to thin it down some. Place the lid on your blender and mix until everything combines and is liquified. Pour this over your bread cube mixture.