1. Preheat the oven 350 degrees.
2. In a saute pan heat the olive oil. Once hot over medium heat add the onions, half the sage and a pinch of salt. Let this saute for 1-2 minutes. Then add the butternut squash and celery for 2 minutes. Pour this mixture into a bowl.
3. Dice the day old No Knead Dutch Oven Bread (the recipe link is in the ingredients and will be below as well), chestnuts, remainder of sage, rosemary, and salt and pepper. Toss this all together. Pour this mixture into an oven proof baking dish and add the vegetable stock.
4. Bake vegetarian butternut squash stuffing for 25-30 minutes. Remove from the oven and allow it to cool before serving. This stuffing can be served at room temperature as well.