This was first made for me by a friend, and I've tweaked it over the years to make it my own. Although it is by no means a healthy recipe to have in your everyday rotation, it makes a very easy and impressive dish to serve for company. The original recipe did not call for mushrooms, so feel free to subsitute another vegetable or leave them out completely. If you like a spicier dish, add chili flakes to taste with the onions, or a bit of hot sauce after the alfredo is added. If you don't want to use liquid smoke, you can replace the fresh salmon fillet with prepared smoked salmon- just begin the recipe with step seven. Serve with garlic bread and a green salad for a complete meal.