Spray microwave-safe container (e.g. mug, ramekin, or egg cooker) with cooking spray or wipe lightly with vegetable oil.
Break one or two eggs into container. Pierce yolks and whites with fork and whisk. Stir in additional ingredients of choice. Cover with plastic wrap, pulling back small area for venting.
Microwave on high for 30 seconds, or on medium for 50 seconds. Let stand for 30 seconds before removing plastic wrap or lid. If still under cooked, turn egg over in container, cover, and microwave for another 10 seconds, or until cooked as desired.