Preparation Time: 5 minutes 

Cook Time: 10 minutes 
Makes : 2 Sandwiches 
Wheat or White bread : 4 Slices 
American Cheese : 4 Slices
Fresh mushrooms: 4 sliced
Onion : 1 small sliced
Salt a pinch 
Butter : To spread on the bread ( better room temperature) + 2tbsp
Heat butter in a pan and sauté mushrooms and onions adding a pinch of salt for 5 minutes. Turn off the stove.
Take your bread, spread some butter on both insides, place the cheese and put half of the onion mushroom mixture, place the other piece of cheese and close it with the second bread piece. Repeat with the second one.
Heat a flat griddle or pan, put some butter and place the sandwiches, fry them on medium to low heat. Flip once the bottom side is golden brown. (The low heat helps cheese to melt). 
Once both sides are done, takes about 5-6 minutes, turn off the stove and enjoy as is or with some soup.