Add in the chopped tomatoes, season with salt and pepper, and cook for a few minutes to combine well. Stir in ground chicken, and let it cook covered for a few minutes till chicken completely cooks through.
Add in the veggies and mix well. If the sauce is too dry, you can add in a bit of water to thin it down. Now toss in the spaghetti, and stir-fry to combine well with the sauce.
Notes
For a gluten-free version, simply opt for gluten-free pasta instead.