Potato Salad with Apples

Place the potatoes in a large pot, add enough cold water to cover, and set over medium heat. Slowly bring to a gentle boil. Cook until the potatoes are tender when pierced with the tip of a sharp knife, about 12 minutes.
☞ TESTER TIP: When cooking your potatoes, be careful not to let a rapid boil creep in as it will break them apart and ruin your salad. (If that does happen, you can always turn them into a mashed potato— just add a lot of butter and crush them with a fork, then season with salt and cracked pepper.)
Gently drain the potatoes and let cool.
In a large bowl, mix all the remaining ingredients together.
Once the steam has dried the potatoes a little and they’re cool enough to handle and, carefully cut them into rough walnut-sized pieces.
☞ TESTER TIP: You want the potato pieces to maintain their shape rather than break when you do this, so use a gentle touch as you handle them.
Add the potatoes to the bowl and, using a light touch, fold them into the dressing until completely coated.
☞ TESTER TIP: If you’re using homemade instead of store-bought mayo, you may need to add more—up to 1 cup more—in order to stretch the dressing to coat the potatoes as homemade doesn’t contain all the emulsifiers as the jarred stuff.
Taste and adjust seasoning as needed. Serve immediately or cover and refrigerate for up to several hours, which will cause the intensity of the mustard flavor to mellow and the rest of the flavors to meld.