Line a mixing bowl with cheesecloth or a clean kitchen towel. Shred the potatoes with a cheese grater (I highly recommend a rotary cheese grater) and then rinse them In a strainer or colander.
Place the shredded potatoes in the bowl with the cheesecloth. Twist the cheesecloth around the potatoes and squeeze to remove any excess moisture. You want your potato shreds as dry as you can.
Dump the potatoes back into the mixing bowl and add the garlic, onion powder, salt, pepper, nutritional yeast, oil, and cornstarch. Mix with a spoon or your hands until well combined.
Heat a waffle iron and spray with non-stick spray.
Once the waffle iron is heated, place enough hashbrowns to completely cover the iron. You don't want it too thick or it won't be as crispy.
Close the waffle iron and cook for 12-15 minutes. This may vary depending on your iron's heat.
While the waffles are cooking, chop your chives and garlic. Mix the sour cream and garlic together in a small bowl.
Remove the hashbrown from the iron and repeat with the remaining hashbrowns until they are all cooked. Tip: If you want them even crispier, place them in an air fryer for 3-5 minutes.
Top with chopped chives and if desired add some flaky sea salt. Serve warm with garlic aioli for dipping.
Leftovers keep in the fridge in an airtight container for about 3 days but note they do lose their crispiness so they are best consumed the same day.