Nothing will make a grilled cheese sandwich truly low fat, but if you use lowfat cheese, and this method you can save a great many calories, and a lot of fat.
Prepare your cheese, whether you need to slice it, or if it is pre-sliced, and place it on half the bread slices. Don’t butter the bread! This is how you will save all that fat.
Heat the grill or pan that you will use. When it is medium hot put, at most, a half pat of butter/ oleo (or substitute that will work for cooking) in the spot where the sandwich will sit and spread it around with a spatula. If the grill is hot enough this will dance a little, but not turn brown. Place the bread with the cheese on it over the spot you have just greased, and then place the other slice of bread on top. Let that sit until the bread is golden. Mine took almost exactly two minutes, but this will depend on your surface and the temperature.
Remove the sandwich temporarily to a plate or some other location on the grill. Then use the same amount of butter and grease that spot again. Put the sandwich with the untoasted side down on the new buttered spot and let that side toast for another couple of minutes.
Remove to a plate and you are ready to eat!
If you used real butter there are 36 calories and 4g of fat in one pat. If you had buttered the bread ahead of time, it’s difficult to get enough on without using at least twice that much, so you have saved yourself that much. If you used oleo, the values for Imperial are 20 calories and 2.5g of fat.
While those don’t sound like big values, that is really a minimum amount saved since most people use lots of butter in order to cover the bread completely. And, if you are trying to watch calories, just ask anyone how much work it is to exercise off even 36 calories!
The sandwiches still taste great, because the pre-melted butter is spread and covers the bread evenly. I actually managed to fool a family of all boys for the entire time that they were growing up. They never knew that I wasn’t slathering those sandwiches in butter!