Bring a large pot of salted water to a rolling boil. Add the rotini and cook according to package directions until al dente. Drain and rinse under cold water.

In a medium skillet, add the lean ground beef and cook until fully browned. Stir in taco seasoning and water, cooking until thickened.

In a large bowl, combine cooled rotini, seasoned ground beef, black beans, corn, cherry tomatoes, and shredded cheese. Mix well.

In a separate bowl, whisk together the Catalina dressing and sour cream until smooth. This will enhance the flavors.

Pour the dressing over the pasta mixture and gently fold to coat all ingredients evenly.

Sprinkle crushed Doritos and shredded lettuce on top if serving immediately. Toss gently before serving.