Place a medium saucepan over medium heat and add 3 tablespoons ham fat or bacon grease; heat for about 1 minute until the fat is shimmering but not smoking.

Sprinkle 3 tablespoons all-purpose flour into the hot fat while whisking constantly to form a smooth roux; continue whisking for about 2 minutes until the mixture turns light brown and smells toasted.

Slowly pour in 1 cup of the chicken or ham stock while whisking vigorously to prevent lumps from forming, then add the remaining 1 cup in a steady stream, maintaining medium heat.

Reduce heat to medium-low and let the gravy simmer for 3 to 4 minutes, stirring occasionally, until it thickens to a gravy consistency.

Stir in 1/2 cup heavy cream slowly while stirring to combine it smoothly into the gravy.

Fold in 1/2 cup diced ham using a wooden spoon, distributing the ham evenly throughout the sauce.

Season the gravy with 1/4 teaspoon black pepper, 1/8 teaspoon salt, and a pinch of garlic powder; taste and adjust seasoning as needed.

If lumps form, strain the gravy through a fine-mesh strainer, then return it to the pan and reheat gently before serving.