- Preheat your oven to 400 F. 
- Brush the inside of the acorn squash with olive oil and season to taste with salt and pepper. - 2 acorn squash, 2 tbsp. olive oil, Sea salt and freshly ground black pepper 
- Place the squash on a baking sheet, cut side up, and roast for 30 minutes, until the flesh is fork-tender. 
- Melt some cooking fat in a skillet placed over medium-high heat. - Cooking fat 
- Cook the sausage until browned and set aside. 
- Add the onions, celery, garlic, and mushrooms to the skillet, and cook for 3 to 5 minutes. - 1 onion, 1 celery stalk, 2 cloves garlic, 4 oz. mushrooms 
- Add the apples and season with salt and pepper to taste. Sprinkle the mixture with cinnamon and sage, and cook for another 2 minutes. - 2 apples, ½ tsp. ground sage, ½ tsp. ground cinnamon, Sea salt and freshly ground black pepper, 1 lb. sausages 
- Combine the meat, the apple mixture, and the beaten egg, and mix well. - 1 egg 
- Divide the stuffing evenly among the squash halves. 
- Place the squash back in the oven for another 15 minutes.