In a large skillet, brown ground beef with onions and garlic on medium heat until cooked through. Drain.
Add taco seasoning, enchilada sauce, diced tomatoes, rotini, water, and enchilada sauce to cooked ground beef mixture.
Bring to a boil, then reduce heat to medium-low. Cover skillet and allow 15 minutes to simmer, or until pasta is tender. Make sure to stir occasionally.
Sprinkle cheese on top and cover skillet, until cheese is melted. Garnish with black olives and green onions if desired.
Recipe by The Domestic Geek Blog at http://www.thedomesticgeekblog.com/summer-recipes-enchilada-skillet/