We do something similar but start with a few slices of bacon and sauté onions, celery, whatever other veggies you like. Stir in tomato chopped or crushed... just a bit. Stir in spaghetti squash. Put back in to squash shell or into casserole. Top with sliced Mozzarella. Bake about 30 minutes at 350 till bubbly and slightly browned.
DD doesn't like squash but loves this! Served it to church ladies group potluck and was told I don't eat squash but they really enjoyed this!