Melt the butter in a medium saucepan, then stir in the flour. Keep stirring for 2 minutes.Slowly add the milk and cream, stirring to incorporate and make a nice smooth roux.Add your spices and the ham (or meat of choice) and cook an additional 5 minutes, stirring frequently.Let the ham mixture cool completely so it's easy to handle.In the meantime, set up your prep station. Eggs beaten in one bowl, breadcrumbs in another, and a place to put the shaped croquetas for cooking.Take a tablespoon of the ham mixture, form it into the desired shape (a small rod or a ball is traditional) and roll in the breadcrumbs. Then dip it in the egg mixture, re-roll in the breadcrumbs, and set aside. Repeat until you've used all the ham.If you plan to freeze any, do so here.If you plan to fry: Heat about 2 inches of oil in a small saucepan over medium heat. Fry the croquetas in batches for about 3-4 minutes each and set on a paper towel to drain. Lower the heat if the croquetas are browning too quickly.If you plan to bake: Preheat your oven to 420 F and bake the croquetas for 12-15 minutes, turning halfway through if desired.