OK here we go...a recipe to impress. It requires similar ingredients to what you already have since you can't find the boursin:
I'll also include some hints since you said you didn't know that much about italian cooking.
Rich's Chicken Alfredo
Before you cut up the chicken, pat it dry with a paper towel. Do this again after you cut it up if you need to. Reason for this is that you want to sear the chicken, not poach/steam it which is what will happen if it's too damp.
Cut up the chicken like it says, brown on all sides in olive oil
Add about 1/2-1 cup of sliced mushrooms. (Not as much as in that recipe) more olive oil if needed.
Brown those as well, according to your recipe.
Reduce heat to low.
Deglaze the pan with some dry white wine (1 tbsp) if you have it, or chicken broth.
Add 2 tablespoons butter, heat until melted
Add 1 1/4 cups heavy/whipping cream
Increase heat to medium
Add salt and pepper to taste
Gradually Stir in 2/3 Cup grated parmesean cheese (Don't use the stuff in a can, italians call that sawdust!)
Dash of nutmeg (optional)
This is when I normally throw the pasta in a pot.
Stir sauce / chicken over medium to low heat until the sauce has thickened. About 5-10 mins. Don't let it burn.
Once the fettucine is cooked and drained Add the sauce/chicken mixtue
Stir in 1 tbsp fresh italian flat leaf parsley. (Never used dried, save that stuff for New Years' Eve Confetti, that's all it's good for.
Serve Immediately.
Some thoughts on cooking Pasta:
You want to season the water with lots of salt or the pasta will be bland. So add it in ahead of time so it can dissolve.
When you put the long fettucine in the pot, use a wooden spoon to push the side sticking out into the water so it doesn't stick then stir it around. You can also dip both ends in olive oil before putting them in the water. I personally don't beleive that adding the oil to the water does anything, they don't mix and there's not enough floating in there to coat the pasta as it enters the water. So that's why I just dip the ends in a little bit.
Pasta is done when it's "al dente" (translation: to the teeth) which means it's still has some bite to it (little bit of white inside) and not soggy. Pasta continues to cook after it's out of the water so you don't want it over done in the pot.
Hope this helps. If you have way too many mushrooms left over, let me know and I'll give you an easy recipe for my stuffed mushrooms that you can serve for starters.
Have a good night! Cheers,
Rich