What could be as convenient to prepare as a grilled cheese sandwich? All ingredients can be bought at the convenient store around the corner and can also be kept in the fridge for a long time.
Do not use a toaster. Instead, use the pan to do the work. It is much tastier that way. Fry the toasts with butter, put the cheese on top and continue to heat until the cheese melts down. The bacon is totally optional. To make it a little healthier, use whole wheat bread instead of the white one.