In a large pot bring salted water to a boil. I use kosher salt. The water should be really salty! This is the only time to give the pasta some flavor. Cook pasta for about 8 mins. You want it with a little bite.
Chop up the onion, garlic, mushrooms, And Chicken. Cut up chicken in to bite size chunks.
Melt the butter in a big sauce pan.MED heat. Toss in chicken, cook till white on outside. They should be pink inside still.
Take out the chicken. Add VERY little EVO. Cook the onion for 5 mins, then add the mushrooms for another 5. Add the garlic.
Toss in the chicken and cook for about 10 mins. Add the sour Cream. Cook for another 10 mins on low.
Toss Everything together in the pot. Coat pasta well.