Preheat oven to 350 F. Bake spaghetti squash in 9x13-inch glass baking dish, in the preheated oven for 55 to 60 minutes. (Leave oven on...as you will bake this again for a few minutes after mixing it all together!)You can poke holes in the squash and microwave it for about 15-20 minutes if you are in a time crunch, but I don't think the "spaghetti" part turns out as well when cooked in the microwave. My opinion!
In the mean time, chop broccoli heads, carrots and red pepper. Place in microwavable dish with 1/4 cup of water and cover with plastic wrap. Cook for 5 minutes.
Once squash is cooked, carefully scrape out the spaghetti flesh.
Toss the spaghetti squash, broccoli, carrots and red bell peppers into a baking dish (you can use the same one if you rinse it out), and mix in the cooked chicken. Place back into the oven for 5-10 minutes to heat together the chicken and veggies.
Add a little grated Parmesan cheese as a garnish and enjoy!