Get the crispiest sprouts possible — without using a lot of oil.
Special equipment: a 3.5-quart air fryer
Trim and quarter the Brussels sprouts and toss in a large bowl with the olive oil and 2 teaspoons salt. Set the air fryer to 390ºF and preheat a 3.5-quart air fryer for 5 minutes. Transfer the sprouts to the air fryer and cook, tossing halfway through, until well-browned and crispy, about 18 minutes.
Transfer to a serving bowl and toss with the Parmesan and lemon zest.