Cook the pasta: Bring a large pot of salted water to a boil. Cook pasta until just al dente. Drain and rinse briefly under cool water to stop cooking. Shake off excess water well.

Prep the chicken and veggies: Dice or shred the cooked chicken. Chop dill, slice celery, dice cucumber, and finely mince red onion. Thaw peas under cool water and drain.

Make the dressing: In a large bowl, whisk together mayonnaise, Greek yogurt, olive oil, lemon zest, lemon juice, Dijon, and garlic. Season with 1/2 teaspoon salt and 1/4 teaspoon pepper to start. Stir in chopped dill.

Toss it together: Add the cooled pasta to the bowl with the dressing and toss to coat. Fold in chicken, celery, cucumber, red onion, and peas. If using capers or pickles, add them now for extra tang.

Adjust and rest: Taste and add more salt, pepper, or lemon as needed. If the salad looks tight, add a splash of olive oil or a spoonful of yogurt. Let it rest in the fridge for 20–30 minutes to meld flavors.

Serve: Garnish with extra dill and a grind of black pepper. Serve chilled or at cool room temperature.