Heat oil in a large heavy skillet over medium-high heat. Brown chicken on both sides then remove to a baking dish and bake at 400F/200C for about 20-25 minutes until cooked through. Internal temperature should be 170F/85C. Tent with foil to keep warm
To make sauce, in the same pan you browned the chicken in, add the garlic and cook over medium heat just until it’s fragrant, a little less than a minute.
Add the cream, stock, Italian seasoning and cheese; whisk together well and cook over medium-high heat about 5 minutes until it begins to thicken.
Add the spinach and sun-dried tomatoes; stir well and heat about 1 minute.
Add the chicken back to the pan and coat with the sauce. Simmer about 5 minutes.
Serve over the pasta.
Notes
If using frozen spinach, squeeze out the excess water.Parmesan may be substituted for the Romano cheese.