This is the general recipe that I follow. It is definitely one that you can play around with depending upon your preferences. Enjoy!
Basic Alfredo Sauce
Many different variations can be made by adding cooked chicken, mushrooms, asparagus, broccoli, seafood, artichokes, fresh herbs, or whatever else is leftover in the fridge. You could even stir/wilt fresh spinach into the sauce over low heat once it is finished. Our favourite version of this uses leftover grilled chicken and fresh broccoli.
12 oz. cooked pasta (I always just use the full pound of pasta and haven't had an issue with too little sauce, but if you like your pasta really saucy, stick with the 12 oz. amount)
1 cup reserved water that the pasta was cooked in (you want the hot, starchy water, not just tap water)
2 cups heavy cream
1/2 tsp. salt
1 cup grated Parmesan cheese
1 garlic clove, minced
Freshly ground black pepper
Add-ins (chopped grilled chicken, broccoli, sliced and cooked mushrooms, etc.)
Start by cooking the pasta in boiling salted water, according to package directions, before you begin the sauce. Feel free to add chopped veggies such as broccoli, asparagus, etc. to the pasta water while the pasta cooks. I usually use broccoli and find that putting it into the pot with the pasta 5 to 6 minutes before the pasta is done cooks it perfectly. Reserve one cup of the hot water the pasta was cooked in before draining. Cover to keep warm
Over medium-high heat, add the cream to a sauté pan or skillet. When it bubbles, add the salt. Small bubbles will erupt into larger bubbles when the salt hits it. Stir. When the sauce thickens enough to leave a clean line in the bottom of the pan when you pull a silicone spatula across it, add the one cup of reserved pasta water. Cook over medium-high heat about 3 minutes until it bubbles again and the sauce thickens. (Again, I just follow the tip about being able to draw a quick line through the pan of sauce. Turn off heat. Add the cheese, garlic,and a few grinds of pepper. Taste and add more salt if needed. Add the cooked pasta and any additional ingredients and stir to coat.