Put a pot of salted water on the stove and let it come to a rolling boil.

Once boiling, add the rotini pasta and cook according to package instructions until al dente, about 8-10 minutes.

While the pasta cooks, in a medium-sized bowl, mix the mayo, sour cream, Italian seasoning, and red wine vinegar until creamy and well-combined.

If the dressing is too thick, a splash of water can help loosen it.

Once the pasta is done, drain it and rinse under cold water to stop cooking and cool it down.

Combine the chilled pasta with the diced veggies in a large mixing bowl.

Pour the creamy dressing over the pasta and veggies, making sure everything is well-coated.

Gently toss in olives and red onion (if using), and adjust salt and pepper to taste.

If adding cheese and herbs, fold them in gently.

Transfer the pasta salad to a serving dish or individual bowls and chill in the fridge for at least 30 minutes.