Add 2 Tbsp oil to large skillet over medium low heat and place salmon skin side down. Season top side with salt and black pepper and pan sear salmon for about 2 minutes. If you don't want the skin on, flip salmon over and remove the skin. It should just slide right off!
Season this top side of the salmon with a little more salt and pepper and cook for about 7-8 minutes, covered. Then flip salmon over, re-cover and cook for an additional 3-4 minutes, until center is cooked to your liking. I like to make sure there's barely any dark pink in the center and the meat flakes off nicely. Remove from pan and set aside.
In the same skillet, add remaining 1 Tbsp of oil and saute garlic for 1-2 minutes then add the heavy cream, milk, chicken broth, Italian seasoning and parmesan cheese.
Whisk in cornstarch and let simmer for 1-2 minutes. Add spinach, sun-dried tomatoes, mushrooms and let simmer until spinach wilts and mushrooms are just tender. Add salmon back to pan and serve immediately.
This dish makes extra sauce that goes great over some pasta or rice. Enjoy!