Cook the macaroni noodles in a large pot of salted boiling water until al dente, typically 8-10 minutes. Drain and rinse with cold water.

Wash and chop the celery and any additional vegetables like bell pepper or onion into bite-sized pieces.

In a large mixing bowl, combine canned tuna, cooled macaroni, and all prepared vegetables. Add hard-boiled eggs if using.

Add mayonnaise and season with salt and pepper. Mix well until evenly coated.

Cover and refrigerate for at least 30 minutes before serving.