Place seasoned toasted bread cubes in large mixing bowl. If making your own: Toss bread cubes with 1 tablespoon poultry seasoning and 1/4 teaspoon salt, place on sheet pan and bake at 350 degrees for about 15 minutes until toasted.
Sauté shallot, celery and garlic in 1 tablespoon of either vegetable oil or bacon grease over medium high heat for about 2 minutes. Set aside.
Add remaining 1 tablespoon vegetable oil or bacon grease to pan and sauté chanterelles mushrooms over medium high heat for about 3-4 minutes.
Turn the heat off and add butter to the pan, letting it melt into the chanterelle mushrooms.
Combine shallot mixture and chanterelle mushroom mixture to seasoned toasted bread cubes. Fold in sage.
Whisk egg into broth and combine with toasted bread cube mixture until completely coated.
Place stuffing mixture in a prepared baking dish, cover with foil and bake for 40 minutes at 350 degrees. Remove foil for the last 10 minutes if you like a crispier top.