Cook spaghetti squash however you prefer. I have a method that I use here.
Scoop out all spaghetti squash strands and place in a large bowl.
In a saute pan, heat olive oil. Add onion and cook about 2 minutes. Add ground turkey, salt, pepper, and minced garlic and cook until no longer pink. Turn off heat and add to bowl with spaghetti squash.
In a small bowl, mix together ketchup, mustard, greek yogurt, and pickles. Pour into bowl with spaghetti squash and turkey.
Whisk three eggs in leftover sauce bowl, then add to spaghetti squash mixture.
Add half of the cheese into spaghetti squash mixture and then stir up the entire mixture very well so everything is very well combined and mixed together.
Pour into greased dish and top with remaining cheddar cheese.
Bake for 1 hour. Let cool 15 minutes before serving.