Preheat oven to 350 degrees.
Add water to a medium sauce pan and bring to a rolling boil. Add macaroni and bring back to boil, stirring occasionally. Cook for approximately 8 minutes.
While the pasta is boiling, brown ground beef, breaking into small pieces and drain grease if necessary. Set aside.
In same pan, add butter and melt. Remove from heat and add flour. Add back to low heat and stir in sour cream and milk. Constantly stir for several minutes until mixture is thoroughly heated and starts to thicken.
Add in cheese by stirring in an about ½ cup at a time until cheese is melted into the sauce and smooth.
After pasta is finished, drain and run under cold water.
Mix together macaroni, beef, cheese sauce and olives and place in large casserole dish. Pour enchilada sauce over the top of the macaroni mixture. Top with additional cheese and olives. Bake for 30 minutes.
If desired, finish under broiler for 2 minutes to make the cheese topping browner and crispier.