Sauté garlic in 1 Tbsp olive oil until lightly brown then set garlic aside.
Cut chicken into bite-size pieces. Cook chicken, and onion in same skillet with remaining olive oil until chicken is white throughout, seasoning with salt and pepper as preferred.
Add tomato paste, cooked garlic and mix well.
Add crushed tomatoes, basil, pepper and water and mix well. Bring to boil, then lower to a simmer and covering sauce with a lid for an hour. Stir occasionally and season with salt and pepper as desired.
This is a good time to get ready for the pasta. Set a large pot of water up to boil the pasta in and set temp on high. You want the water to be boiling and it takes awhile.
During last fifteen minutes or so of cooking the marinara sauce, add the squash. At this start to cook pasta according to directions on package.
In large bowl, pour sauce over cooked pasta and mix well.
Sprinkle parmesan or asiago cheese on top and serve!