Place beef, pickled onions, breadcrumbs, egg and seasoning in a food processor and lightly blitz. A food processor will make the mixture quite smooth. For a more rustic result chop the onion and mix ingredients together with a fork.
Using a pudding spoon, take spoonfuls of the mix and shape into meatballs. Place on a plate and chill until ready for use.
Heat oil in pan and brown the meatballs on all sides, shoogling the pan gently to keep them moving.
Reduce heat and continue cooking for about 10 minutes. Cut open one meatball to check they are thoroughly cooked through with no pink or use a thermometer probe. The internal temperature should exceed 75 degrees C.
Serve with mashed potato, bramble jelly or ketchup and extra pickled onions. Alternatively you can make delicious burgers with the same mix.