Roughly chop the onion and stir-fry it with a little oil until fragrant.
Add sliced onion and garlic, and then add to the sautéed onions.
Add ground beef.
Cook until the meat cooked through.
Add the Worcestershire sauce, pepper, sugar and salt, mix well and set aside.
Melt butter, reduce heat and add the flour in.
Stir until well blended, and then add milk, stirring constantly until evenly distributed.
Add ground meat into the batter, continue to stir until well blended.
Season with grated nutmeg, pepper, salt and sugar.
Set aside and allow to cool.
Take 1 tablespoon full of dough, shape dough to little balls, fill it with cheese and jerky pieces, and then coat each ball with flour and beaten eggs.
Fry bitterballen until golden.