In a medium bowl, add cashews, cover with boiling water, cover the bowl with a plate, and set aside 30 minutes. Otherwise, cover with cold water and soak overnight.
Cook the potatoes
Place the unpeeled potatoes in a large saucepan and cover with cold water. Cover the pan and bring the water to a boil.
Reduce to medium heat and cook for about 10-15 minutes or until a knife inserted in the center of the potatoes easily goes in and out. If you used potatoes of different sizes, the smallest ones will cook faster. Remove these first with a slotted spoon, set aside in a bowl. and keep cooking the biggest one until they pass the knife test.
Drain the water from the saucepan, pouring the potatoes into a sieve over the sink.
Cool potatoes for 5 to 10 minutes in the sieve to give time for the steam to evaporate. Meanwhile, prepare the sauce.
Drain the cashews and place them in a high-speed blender.
Add in all the sauce ingredients in this order: water, lemon juice, vinegar, oil, maple syrup, mustard, salt, garlic powder, and dill.
Blend at high speed until it forms a creamy sauce. You may have to stop the blender, scrape down sides and repeat until all the ingredients come together into a creamy sauce If too thick, adjust by adding more water, 1 tablespoon at a time, blending between each addition.
Assemble the potato salad
Peel the potatoes if you like and roughly chop the lukewarm potatoes into 1 cm chunks.
Place the potato chunks in a large salad bowl.
Add in the finely chopped vegetables: celery, dill pickles, and red onion.
Pour the cashew sauce onto the salad bowl and toss vegetables together.
Refrigerate for few hours before serving to enhance flavors or serve lukewarm.
Store in an airtight container in the fridge for up to 4 days or simply cover the salad bowl with a silicone lid to seal.