Preheat oven to 400 degrees f.
Bring a large pot of water to a boil. With a spoon, scrape out the seeds of the squash. I simply toss the seeds because the center is very watery.
Dip the squash in the boiling water for 1 minute, then place on a towel to dry.
Arrange squash like little boats on the bottom of a baking dish. Set aside.
Brown meat in a large skillet. Add taco seasoning, onion, bell pepper, tomato sauce, and salsa. Cover and simmer 15 minutes.
Fill each squash boat with the taco meat mixture, then top with cheese. Cover with foil and bake 25 minutes or until squash is soft and cheese is melted.
Garnish with green onion, and serve with additional salsa.