Chop the salad ingredients, so they're ready to go. Dice the hard-boiled eggs, bell pepper, onion, and celery.
Boil the macaroni until tender, then drain it in a colander. Briefly rinse the pasta with cool water to cool it off.
While the macaroni is boiling, prepare the dressing. Stir together the mayonnaise, Dijon, relish, red wine vinegar, sugar, salt, and pepper.
Combine the cooled and drained macaroni, egg, bell pepper, celery, and onion in a bowl. Pour the dressing over top, then stir until everything is well combined and coated in dressing.
Serve the macaroni salad immediately or refrigerate until ready to eat. Chilling it for at least 30 minutes makes it taste even better! Enjoy.
*Gluten-free pasta can be used, but choose a small shape (ideally macaroni if you can find it!) and cook it just until tender according to the package directions. Rinse briefly with cool water, drain very well, and stir gently because gluten-free pasta can be more delicate. **Dijon mustard gives the dressing a smooth, savory sharpness without making the dressing taste too mustardy. Yellow mustard can be used in a pinch, but it has a stronger color and a more classic mustard flavor, so start with a little less and add more to taste.***Red wine vinegar adds a tangy flavor that wakes up the creamy mayo dressing. Apple cider vinegar is the closest swap and will taste a little fruitier, while white vinegar is sharper. Lemon juice can also work, but it gives the salad a brighter, more citrus-forward flavor.****There are two main camps when it comes to macaroni salad: sweet and not so sweet. I like mine with just a touch of sweetness to balance the acidity and creaminess of the dressing, so that's what you'll get with this recipe. If you like yours sweeter, you can simply add more sugar to taste (up to about ¼ cup sugar).Want to add some garlic? If you like a little garlic flavor, add ¼ tsp garlic powder to the dressing. I prefer garlic powder here because it blends smoothly into the mayo dressing and gives a mellow, savory flavor without the sharpness of raw garlic.Make it ahead: Macaroni salad lasts about 3-4 days in the fridge when stored in an airtight container. For the best flavor, chill it for at least 30 minutes before serving so the seasonings in the dressing and the crunchy vegetables have time to meld.