• Place 5-6 clean, medium potatoes in a large pot, cover with cold water, and season well with salt. Turn the heat to medium-high to bring the water to a boil. Once the water is boiling reduce to medium heat so the water doesn't boil over the edge of the pot. Boil the potatoes for 20-30 minutes or until they're fork tender potatoes. The amount of time will vary depending on how big your potatoes are.
• While the potatoes are cooking, prepare the hard-boiled eggs.
• Drain the potatoes and allow them to cool to room temperature. Not only are cool potatoes easier to handle, but they also allow the starch cells walls to close up so that the potatoes don't absorb all of the dressing, resulting in a creamier salad.
• With the side of a paring knife, gently scrape the potato skins off. The thin skins will come off of the cooked potatoes easily. Dice potatoes into large chunks, roughly 3/4 of an inch, and add to a large bowl.
• Add the diced onion, diced hard-boiled eggs, and pickle relish to the same bowl as the cubed potatoes. 
• To create the creamy dressing, add mayonnaise, sour cream, mustard, and sweet pickle relish in a small bowl and stir until combined. Pour the mayo mixture over the potatoes and stir by lifting the potatoes as you rotate the bowl to work the dressing in. Do your best to not crush the potatoes. 
• Wait until all of the ingredients are mixed and taste the potato salad before add any salt. Start with 1/2 tsp and add more if needed. The amount of salt will vary depending on how well the water was salted when cooking the potatoes.
• My grandma would cover the potato salad with slices of hard-boiled eggs and then sprinkle the top with paprika. This step is optional but makes for a really pretty presentation.

Storing Instructions

• Since the potato salad has mayo in it, it's suggested to keep it cold when serving. Store any leftover potato salad in an airtight container in the refrigerator for up to 5 days.