Step 1

Bring a large pot of heavily salted water to a boil. Add the macaroni and cook according to package directions until tender. Meanwhile, make the dressing.

Step 2

Place the mayonnaise, yogurt, vinegar, mustard, 1 teaspoon salt, and pepper in a large bowl and stir to combine. Add the trout, celery, apple if using, dill, and chives, and gently stir to combine; set aside.

Step 3

Drain the macaroni, rinse under cool water until cooled, then drain well again. Add to the bowl of dressing and gently stir to evenly coat. Taste and season with more salt and pepper as needed. Cover and refrigerate for at least 30 minutes before serving.