Begin by bringing a large pot of salted water to a rolling boil. Add the rotini pasta and cook according to the package instructions, typically around 8-10 minutes until al dente. Drain and rinse under cold water.

In a large skillet, cook the lean ground beef over medium heat for 5-7 minutes until browned. Drain excess grease, stir in taco seasoning and a splash of water; cook for another 2-3 minutes.

In a large mixing bowl, combine the cooked rotini, seasoned beef, black beans, corn, halved cherry tomatoes, and shredded fiesta blend cheese. Mix until evenly distributed.

In a small bowl, whisk together the Catalina dressing and sour cream until smooth.

Pour the creamy dressing over the pasta mixture and toss until everything is thoroughly coated.

If serving immediately, gently fold in crushed Doritos and shredded lettuce. If preparing ahead, reserve these ingredients until just before serving.