In a mixing bowl, whisk the fish sauce and sugar together until the sugar dissolves.

Place the chicken wings and garlic in a plastic zipper bag or large bowl and pour the fish sauce marinade over the chicken. Massage or toss the chicken to make sure every piece is coated.

Seal the bag or cover the bowl and marinate for at least 2 hours in the fridge, but I recommend doing it overnight!

Heat the canola oil in a Dutch oven over medium heat or a deep fryer to 300°F

Drain the marinade from the wings. Add the potato starch to a shallow bowl or sheet pan.

Coat the wings thoroughly on both sides in the potato starch, tap off any excess, and set on a rack nested in a sheet pan.

Working in batches, carefully add a single layer of wings to the hot oil until the chicken flesh turns opaque and the starch no longer looks dry and powdery, 5 to 6 minutes.

Use tongs to remove the wings back to the rack. Bring the oil back up to temperature and repeat with the remaining wings.

Raise the oil temperature to medium-high or 350°F. Again, working in batches, carefully add the wings back to the hot oil in a single layer until the skin crisps up and toasts to a nice brown, an additional 4 to 5 minutes.

Drain the wings on a clean rack nested in the sheet pan. Bring the oil back up to temperature and repeat with the remaining wings.

Transfer the wings to a platter and garnish with the scallions and fried shallots.