Finely chop the cooked Halal chicken or turkey ham and grate the cheese of your choice, setting them aside in separate bowls. Gather all your other ingredients like flour, butter, milk, and spices.

In a medium saucepan, melt 3 tablespoons of unsalted butter over medium heat. Once melted, add 3 tablespoons of all-purpose flour, stirring constantly for about 2-3 minutes until the mixture forms a smooth white paste with a light golden hue.

Gradually whisk in 1 cup of whole milk into the roux, ensuring a lump-free texture. Cook this mixture over medium heat, stirring constantly for about 4-5 minutes until it thickens and coats the back of a spoon.

Remove the pan from heat and stir in optional mustard powder, nutmeg, and salt and pepper to taste. Mix well until all the ingredients are fully combined.

Once seasoned, fold in the chopped ham and grated cheese, mixing everything together thoroughly. Allow the filling to cool slightly before transferring it to the refrigerator for about 15 minutes.

After chilling, scoop a tablespoon of the filling and mold it into small balls or ovals with your hands.

Set up a dredging station with three shallow bowls: one with flour, another with beaten eggs, and the last with panko breadcrumbs. Roll each shaped croquette first in flour, followed by the egg, and finally coat it generously in panko.

In a deep frying pan, pour enough vegetable oil to submerge the croquettes and heat it to 350°F (175°C).

Carefully add the coated croquettes to the hot oil in batches to avoid overcrowding. Fry them for about 3-4 minutes or until they turn golden brown.

Once fried, transfer the croquettes to a paper-towel-lined plate to absorb excess oil. Allow them to cool slightly before serving.