Cook pasta according to package.
Reserve ½ cup of pasta water before draining the pasta.

While the pasta is cooking, heat 1 tablespoon of olive oil in a large, heavy-duty pan over medium-high heat.
Add the finely chopped onion and cook for 2-3 minutes, or until softened.
Add the minced garlic and 1 tablespoon of butter to the pan and sauté for 30 seconds. Add the chicken pieces and seasonings.
Sauté the chicken for 3-5 minutes, or until browned and cooked through

Stir in the heavy cream, reserved pasta water, grated Parmesan cheese, chopped sun-dried tomatoes, and spinach.
Bring the mixture to a simmer and cook for 3-4 minutes, allowing the sauce to thicken slightly.
Taste the sauce and adjust the salt and other seasonings as needed.

Toss the cooked pasta into the pan with the creamy chicken sauce.
Stir well to ensure the pasta is fully coated with the sauce.
Garnish with fresh chopped basil if desired.
Serve immediately while hot.