Toss halved and trimmed brussels sprouts with melted bacon grease and spices in a large bowl.
Transfer brussels sprouts to air fryer.
Using the manual settings, set air fryer to 400 degrees for 10 minutes.
Halfway through cooking time, remove fryer basket and give the brussels sprouts a gentle toss. Return basket to air fryer.
After 10 minutes, transfer brussels sprouts to serving dish and finish with the juice and zest of half a lemon.
Enjoy!