Bring a large pot of salted water to a boil and cook the rotini according to package instructions until al dente—this is crucial for the right texture in the final salad. Drain the pasta thoroughly, then rinse it under cold running water, stirring gently with your hands until completely cooled. This stops the cooking process and prevents the pasta from becoming mushy when mixed with the dressing.

While the pasta cools, finely dice the red onion, seed and chop the roma tomatoes (removing excess liquid helps prevent the salad from getting watery), slice the pepperoncinis, and chop the romaine into bite-sized pieces. I like to prep the tomatoes last and pat them dry with paper towels to keep the salad from becoming soggy. Keep the lettuce separate for now—it will go on top just before chilling.

Transfer the cooled pasta to a large bowl and add the diced red onion, chopped tomatoes, sliced pepperoncinis, freshly grated parmesan, black olives, and dried oregano. Toss everything together gently but thoroughly to distribute the ingredients evenly throughout the pasta.

Pour the Italian dressing over the pasta mixture and toss well, making sure the dressing coats everything evenly—this is where the flavors really come together. Top the dressed pasta with the chopped romaine lettuce, but don't mix it in yet; I keep it on top so it stays crisp and fresh rather than getting wilted by the dressing.

Cover the bowl and refrigerate for at least 1 hour to let the flavors meld and the pasta absorb the dressing. Just before serving, stir everything together well, folding the lettuce into the pasta salad and redistributing all the ingredients and dressing evenly.