Melt the butter in a saucepan over medium heat. Stir in ½ cup of the flour and cook for about 2 minutes, stirring constantly, to form a roux. Gradually whisk in the milk until smooth.
4 tablespoons unsalted butter, 1 ½ cups all-purpose flour, 2 cups whole milk
Add nutmeg, garlic powder, onion powder, salt, and pepper. Cook, stirring often, until thick and smooth. Stir in the chopped ham and cook for 1–2 minutes.
Pinch of ground nutmeg, 1 cup serrano ham, 1 teaspoon garlic powder, 1 teaspoon onion powder, Salt and black pepper
Transfer the mixture to a shallow container, cover, and refrigerate for at least 12 hours, or until very firm.
Once chilled, shape the mixture into small logs or oval croquettes.
Set up two bowls: one with beaten eggs and one with bread crumbs. Dip each croquette into the egg, then coat fully with bread crumbs.
2 large eggs, Bread crumbs
Heat oil in a deep pan to 350°F (180°C). Fry croquettes in batches for 3–4 minutes, turning occasionally, until golden and crisp. Transfer to paper towels to drain excess oil.
1 cup oil
Serve hot with your favorite dipping sauce.