To top spaghetti squash my husband makes an alfredo-like sauce out of coconut milk. . . super good! Put some chicken thighs on top of that - it's one of my favorite meals.
I have to admit that we eat cauliflower far more often than squash, though. He makes a delicious "pizza crust" out of cauliflower and some almond meal and throws some pesto, chicken and broccoli on top. Equally as delicious! More often we eat it simply tossed in some olive oil and roasted in the oven.
Let us know how the experiment goes!