For the Homemade Tomato Sauce (optional):
In a medium sauce pan over medium low heat, combine olive oil, garlic, onion and crushed red pepper, and cook 2 to 3 minutes, stirring constantly so the garlic does not burn. Add tomatoes, basil, salt and pepper. Bring to a low simmer, reduce heat to low, and cover. Let cook for 20 minutes.
For the Roasted Spaghetti Squash:
Preheat oven to 400F. Line a baking sheet with parchment paper.
With a sharp knife, carefully cut about four 1/2-inch slits in the squash to allow steam to escape while it cooks. Put the squash on the prepared baking sheet and roast for about 1½ hours. Let the squash cool for about 20 minutes on the baking sheet.
Cut the squash in half and use a spoon to scoop out the seeds. With a fork, pull the squash fibers away from the outer peel (use a towel to hold the squash in place if it's too hot). Season with salt and pepper if desired.
For the Skillet Chicken Parmesan:
Preheat oven to 400F.
Arrange a chicken breast between two sheets of plastic wrap. Using a meat mallet, pound the chicken evenly until it is 1/4-inch thick. Remove the plastic wrap and repeat. In a small bowl, combine the salt, pepper and garlic powder. Season each side of each chicken breast with the mixture.
Heat oil in a large ovenproof skillet over medium high heat. Place chicken breasts in the skillet and sear for 3 minutes. Use a spatula or tongs to flip the chicken breasts. Top with sauce, mozzarella and Parmesan. Transfer skillet to the oven and bake for about 4 to 5 minutes, until chicken is cooked through and cheese is melted and bubbly. Serve with Roasted Spaghetti Squash.