Heat a large skillet over medium high heat. Add the oil and brown the ground beef.
As the beef is cooking, slice the mushrooms and add the mushroom slices to the partially cooked ground beef.
Combine the seasonings as that finishes cooking.
Add all other ingredients, except sour cream, to the cooked beef. Stir to combine and cover.
Bring to a boil, then lower heat to medium low and allow to simmer for 10-12 minutes, or until the noodles are cooked through. The time may vary depending on the type of noodles you use. Read the directions on the package. This gluten free Barilla fettuccine takes 13-14 minutes, but white spelt pasta takes 7 minutes!
Add the sour cream and stir. If it is too watery, let sit for 5 more minutes. Serve immediately.