Preheat oven to 400 degrees.
Cut the stems off the acorn squashes, than cut in half starting from the top. Place upside down in a cake pan or cookie sheet. I usually pour in about an inch of water into the cake pan to prevent the inside of the pan from turning brown. Bake squash for 30 minutes or until acorn squash pierces easily with a fork.
While the squash is roasting, make the stuffing. Dice a small red onion & saute in butter or oil of choice, I use vegan butter by Miyoko, see recipe notes.
Once onions are softened, add 1 TBSP dried sage and cook for another 2 minutes. Set aside add in a medium bowl.
Next cook the sausage and add 1/2 tsp each of salt & black pepper to the sausage. Once sausage is cooked mix it with the red onions.
I usually wait to scoop out the seeds in a squash till it's roasted, but if you want to roast the seeds for snacks, scoop them out before roasting the squash.
Sprinkle the insides of the squash with salt & black pepper. Stuff all 4 halves with the sausage stuffing and sprinkle with cheese if desired. Roast again till cheese is melted and slightly browned & crisp.