Cook the rotini pasta in a large pot of salted boiling water according to package instructions, about 8-10 minutes, until al dente. Drain and rinse with cold water.

In a small mixing bowl, whisk together sour cream and taco sauce until combined. Set aside.

Cook the ground beef in a large skillet over medium-high heat for 5-7 minutes until browned. Drain excess fat and season with salt, pepper, taco seasoning, and garlic if desired. Stir in salsa and cook for another minute.

In a large salad bowl, combine cooled rotini pasta with the cooked ground beef mixture, chopped lettuce, corn, halved tomatoes, diced onion, and chopped cilantro.

Drizzle dressing over the salad; toss gently to combine until evenly coated.

Serve immediately or chill for 30 minutes to let flavors meld. Add fresh greens just before serving if prepared in advance.