Skinny "Mac & Cheese"

The recipe calls for:
5 1/2 cups spaghetti squash
1 tbsp butter
1 tbsp olive oil
1/4 onion, minced
1/4 cup flour
2 cups skim milk
1 cup fat free chicken or vegetable broth
8 oz reduced fat cheddar cheese, shredded
4 cups baby spinach
1/8 cups parmesan cheese, grated
salt & pepper, to taste

-- Preheat the oven to 375.
-- Cook the spaghetti squash, see post.
-- Heat the butter and oil in a large saucepan on medium heat. Add the onions and cook for 2 minutes.  Stir in the flour, reduce the heat to low and stir continually for 4 minutes.  Add the milk and broth while whisking continually, raise the heat to medium/high until it starts to boil and become thick and smooth, about 2 minutes.  Season with some salt/pepper.
-- Remove the sauce from the heat once it's thick then add the cheddar cheese until, stir until it is fully melted.
-- Add the cooked spaghetti squash and baby spinach a little at a time while mixing it all together.
-- Pour it all into a baking dish, sprinkle with parmesan cheese and bake for 25-30 minutes.