While you fill a large pot with salted water for the pasta, prepare all your vegetables and herbs. Peel the cucumber and slice it into 1/4-inch rounds, halve or quarter the cherry tomatoes, thinly slice the red onion, and chop the fresh dill, parsley, and basil. Having everything prepped and ready means you can work quickly once the pasta is done cooking, ensuring the best texture and flavor in your final salad.

Bring the salted water to a boil and add the rotini pasta, cooking according to package directions until al dente. You want the pasta to have a slight firmness so it doesn't turn mushy when mixed with the wet dressing. Drain the pasta thoroughly but do not rinse it—the starch on the pasta helps the dressing cling to it.

In a small bowl, whisk together the sour cream, mayonnaise, red wine vinegar, Dijon mustard, sugar, garlic powder, salt, and black pepper until smooth and well combined. I like to taste the dressing at this point and adjust the seasoning—if it needs more tang, add a touch more vinegar; if it needs more creaminess, add a bit more mayo. The dressing should be pourable but thick enough to coat the pasta evenly.

Let the hot pasta sit for about 5 minutes to cool slightly—this prevents the vegetables from wilting and allows the pasta to firm up. Transfer the warm pasta to a large mixing bowl and immediately pour the creamy dressing from Step 3 over it, tossing gently to coat. Add the prepared vegetables and herbs from Step 1 and mix everything together until fully combined and evenly dressed. I find it helpful to let the salad sit for 10-15 minutes before serving so all the flavors can meld together beautifully.