Preheat the oven to 350°F.
Cut spaghetti squash in half, remove seeds, and bake until tender, about 40 minutes.
Once cooled, shred the spaghetti squash flesh with a fork to create noodles.
In a nonstick skillet over medium heat, cook ground turkey until browned; remove from heat and let cool slightly.
Chop the bell peppers into small pieces.
In a large bowl, combine shredded spaghetti squash, browned turkey, chopped bell peppers, drained corn and black beans, green chiles, diced tomatoes with juices, enchilada sauce, spices (chili powder, cumin, salt), and mix well.
Grease a 9×13 inch casserole dish and transfer the mixture into it.
Sprinkle the 2 cups of cheese evenly over the top.
Cover the casserole dish with foil and bake for 45 minutes.
Remove foil and bake an additional 15 minutes until the cheese is bubbly and slightly golden.
Let the casserole rest for 10 minutes before serving.