Cut the bread into 1” square pieces, toast on the griddle top, and reserve.
Heat butter, then add onions, celery, thyme, sage, and apples. Sweat them all together until the onions, celery, and apples are tender.
Add the toasted bread, mix well, and turn off the stove.
Add chicken stock, chestnuts, salt, and pepper, then mix quickly.
Remove from heat and allow to cool.
Cool further in the refrigerator until ready to serve or reheat.