Quarter or halve baby potatoes based on their size. You're looking for a chunky potato salad but you want each potato chunk to be about bite size.
Add the potatoes to a medium-sized pot and fill with cold water. Set over high heat and boil until just tender. Drain and let cool slightly.
Add potatoes to a large bowl.
To the potatoes add diced egg, green onions, shallot, and parsley, and set aside.
In a small bowl whisk together lemon juice, lemon zest, olive oil, whole-grain mustard, honey, kosher salt, and black pepper.
Pour dressing over the potato mixture and toss to combine. If it looks dry add a few more drizzles of olive oil.
Give it a taste and season with more kosher salt and black pepper if needed.
At this point, you can either let it sit and eat the salad at room temperature OR let it chill in the refrigerator until cold (or even overnight!) and you'll salad will be super flavorful since it was able to rest in the fridge to really absorb all the flavors.