Cook pasta according to the package directions. Drain, and set aside.
In a large rimmed skillet cook the ground beef and chopped onion until no longer pink.
Add the tomatoes, taco seasoning, salt, and pepper. Simmer over medium heat for about 5 minutes.
Stir in ½ cup cheddar cheese, cream cheese, and sour cream. Stir until the cream cheese is melted and the sauce is well blended. Add the pasta to the meat and gently stir. Simmer over medium-low heat 3-4 minutes.
Remove from the heat and top with remaining ½ cup shredded cheddar cheese and black olives.