Preheat oven to 400 degrees and prepare a 9X13 inch pan by greasing it.
In a large pan over medium heat add olive oil and butter and let melt. Add mushrooms and let cook for 3 minutes. Add chopped onions and celery and let cook for 10 minutes until veggies are soft.
Add rosemary and sage, stir and cook for 1 minute. Season with salt and pepper.
Reduce heat to low and add pumpkin and chicken stock and stir. Cook for 5 more minutes.
Place bread cubes (mine were about 3/4 inch cubes) in casserole dish (you can dry them out in the oven before if you would like) and pour veggie/pumpkin mixture over bread cubes. Gently toss to coat evenly and bake for 20 minutes. Bake longer for a dryer stuffing!