Step 1

Peel and thinly slice the onions. You can do this with a sharp knife, a mandolin, or the slicer disk on your food processor, for even-sized pieces.

Step 2

Heat up about an inch of oil in a large, deep pot. Once hot (over medium heat), add the onion and allow them to fry until browned and crispy (2-4 minutes). Stir occasionally to make sure they're frying evenly.If you do this in smaller batches, then it can take as little as 2 minutes per batch. However, I've found that when frying the whole amount, it'll take about 3-4 minutes.For air fryer crispy onions: preheat the Air fryer (if necessary) to 270ºF/130ºC and then lightly spray the basket with oil, add the onions, and spray them with a little oil too. Then Air fry for 20-30 minutes, tossing/flipping the onions every 5 minutes to make sure they brown evenly, until crispy and golden brown.

Step 3

When ready, remove the onions from the oil (with a slotted spoon) and place them over a layer of paper towel to absorb any excess oil (optionally blot the top with a second sheet). You can then enjoy the onion strings directly or season lightly with some salt and pepper first.

Step 4

Make sure to allow the onions to cool entirely before storing; otherwise, they can "steam" and become soggy.

Step 5

Make ahead/Store: you can prepare these crispy onions up to 4-5 days in advance (and store in an airtight container) or up to 2 weeks in advance (stored in the fridge). When using, you can re-crisp them in the oven or Air Fryer at 375ºF/190ºC for just a few minutes.Freeze: allow the crispy onions to cool, then place in a freezer-safe bag and freeze for between 4-6 months.