Add about a tablespoon of water to the bottom of the air fryer basket, then place the grate on top. This will add a bit of moisture and prevent the broccoli from burning or smoking.
Place the broccoli florets into a large mixing bowl. Drizzle the olive oil over the broccoli, then sprinkle the nutritional yeast and garlic salt on top. Secure a lid or sheet of tin foil over the bowl and give the bowl a good shake—this is the best way to ensure even coverage.
Dump the broccoli into to the air fryer basket and give it a little shake to spread the florets out evenly.
Close the air fryer, then cook the broccoli at 400º F for 7 minutes. When done, carefully remove the basket and serve the broccoli immediately.