@user8100454909930: Sauté minced onion in butter, stir in flour, then gradually whisk in milk to form a thick béchamel. Fold in diced ham, grated cheese, nutmeg, and pepper. Chill until firm, shape into balls, and coat with flour, egg, and breadcrumbs. Fry at 175°C until golden and hot throughout. Drain and serve with garlic mayonnaise or mustard.