Peel and cut the russet potatoes into even 1-inch chunks, then place them in a large pot.

Fill the pot with water to cover the potatoes and add a pinch of salt. Boil over medium-high heat for 15-20 minutes until fork-tender.

Drain potatoes and rinse under cold water to cool. Set aside to reach room temperature.

In a mixing bowl, combine mayonnaise, mustard, relish, salt, and pepper. Whisk until smooth and creamy.

Gently fold the cooled potatoes into the dressing with a spatula, ensuring even coating.

Stir in chopped red onion, celery, and hard-boiled eggs gently.

Cover and chill in the refrigerator for at least 1 hour.

Before serving, taste and adjust seasoning if needed, and sprinkle paprika on top.