Cook the pasta: Bring a large pot of salted water to a boil. Add pasta and cook until just al dente. You want it tender with a little bite so it holds up in the dressing.

Chill the pasta fast: Drain and rinse under cool water to stop the cooking. Shake off excess water, then toss with 1 tablespoon olive oil to prevent sticking. Spread on a sheet pan to cool.

Prep the chicken: While the pasta cooks, pull the rotisserie chicken into bite-size shreds. Discard skin and bones, or chop a little crispy skin for extra flavor if you like.

Chop the veggies: Finely chop celery and red onion. Dice the red bell pepper. Thaw the peas by running under cool water, then pat dry.

Mix the dressing: In a large bowl, whisk mayonnaise, Greek yogurt, Dijon, lemon zest and juice, vinegar (if using), garlic powder, onion powder, celery seed, salt, and pepper. Taste and adjust. It should be creamy, tangy, and well seasoned.

Combine: Add the cooled pasta, shredded chicken, celery, red onion, bell pepper, and peas to the bowl. Sprinkle in the herbs and Parmesan, if using.

Toss gently: Use a large spatula to fold everything together until evenly coated. If it seems dry, add a spoonful of mayo or a splash of milk to loosen.

Chill: Cover and refrigerate for at least 30 minutes, ideally 1 to 2 hours. This helps the flavors meld and the dressing cling to the pasta.

Final seasoning: Before serving, taste again. Cold food dulls flavors, so you may need a pinch more salt, pepper, or a squeeze of lemon.

Serve: Garnish with extra herbs and a few cracks of black pepper. Enjoy straight from the fridge or closer to room temp.