rinse , core and slice tomato

peel , rinse and slice onion

pre heat skillet or griddle

butter one side of each piece of bread

on the non buttered side spread thinly the balsamic vinaigrette

when the skillet or griddle is hot put down butter side of bread

put sliced tomato and onion on the other piece of bread. let that cook just a bit. you can also fry the onion for about a minute alone before adding

put a slice of cheese on one piece of bread. once it starts to melt a bit put the bread pieces together and fry until cheese is all the way melted and the bread is nice and toasted to your liking

serve and enjoy