Peel the onions, cut in half and thinly slice. Roll them well in flour and roast the onions in well-drained butter (not too hot). Do not use too little butter, otherwise they will just turn black.
Don`t just stir the fried onions with a wooden spoon, but rather turn them with 2 forks. Drain the roasted onions on a kitchen towel and then let them cool. Can stay there until the next day so that they dry well.
Then pour into a container and store in a dry place, or just make as much as you need for a dish. Since it is self-made, I would not keep it for too long and use it up immediately.
Roasted onions can be sprinkled over salads, soups, mashed potatoes, burgers, hot dogs and much more.