Spanish Ham Croquettes (Croquetas de Jamón)

Name: Spanish Ham Croquettes (Croquetas de Jamón)
Prep time: 30 min
Cook time: 20 min
Total time: 50 min
Cuisine: European, Spanish, Mediterranean
Ingredients: 200 g cured ham (serrano, prosciutto, Iberic, etc.); 150 g flour; 700 ml milk; 75 g butter; ½ onion (finely chopped); 1 tbsp gelatin powder (or three pre-soaked gelatin sheets *optional); ⅓ tsp nutmeg (*optional); 200 g panko (or standard breadcrumbs); 3 eggs; olive oil (or cooking oil of your choice - enough to cover your croquetas.)