In a bowl, toss the beef, oil, onions, bell peppers, chili flakes (optional), salt, and black pepper.
Press Menu and use the START/PAUSE dial to select Menu Preset 24.
Plug the plug-in Grill into the unit in Position 1.
Press START/PAUSE to begin preheating. Once preheated, the unit will beep twice, display “Ready”, countdown for 10 seconds and then beep once. Open the door and place the beef cubes, peppers, and onions on the hot plug-in Grill.