Cook the pasta right: Bring a large pot of well-salted water to a boil.
Cook the pasta until al dente (tender but with a little bite). This usually takes 1–2 minutes less than the package says. Drain and rinse briefly under cool water to stop cooking, then shake off excess water.
Dress while warm: Transfer the pasta to a large bowl.
Add 1/3 cup of the Italian dressing and toss. This early dressing step helps the pasta absorb flavor instead of turning bland later.
Mix the veggies: Add tomatoes, cucumber, red onion, bell pepper, olives, and pepperoncini to the bowl. Toss gently to combine.
Add the goodies: Fold in the salami, mozzarella, and half of the Parmesan.
Add most of the herbs, reserving a little for garnish.
Finish with more dressing: Add another 1/3 to 1/2 cup dressing, tossing until everything looks glossy but not soupy. Taste and adjust with a pinch of salt, black pepper, or a splash more vinegar if needed.
Chill to marry flavors: Cover and refrigerate for at least 30 minutes, ideally 1–2 hours. The flavor deepens as it rests.
Final touches: Before serving, toss again and add a little extra dressing if the pasta has absorbed too much.
Sprinkle remaining Parmesan and herbs on top. Serve cold.