Cook spaghetti squash:
Option #1- Oven: Preheat oven to 400F. Cut in half and place facedown in oven safe dish with ¼ inch water. Bake for 40-45minutes or until fork tender.
Option #2- Microwave: Cut in half and place face side down in ¼ inch of water, cover squash and dish with plastic wrap. Microwave each side for 7-10 minutes, until fork tender.
Option #3: Instant Pot: Cut spaghetti squash in half. Add 1 cup of water to an instant pot and place spaghetti squash in the pot on top of the metal trivet. Press manual and cook for 9 minutes. Release the pressure using the quick release and retrieve spaghetti squash.
Meanwhile, defrost or cook your shrimp up. (I just defrosted them in the microwave.
Scoop out the strands of spaghetti squash to a large bowl, careful not to break the shells. (Don’t worry if you do, you can just bake it casserole style.)
Preheat oven to broil. Combine spaghetti squash, green chiles, enchilada sauce, and green onions. (I had mine cold in the fridge so I microwaved this mixture to move the process along a bit.)
Scoop mixture into shells and place in oven on a shallow baking pan. (Or just place in a 8 x 8 oven safe casserole dish if your boats fell apart.) Top with cheese and broil for 2-3 minutes until cheese is bubbly and crispy golden brown.