Melt butter in a saucepan over medium heat.
Whisk in flour to form a smooth paste.
Cook for 1-2 minutes to remove raw flour taste.
Slowly pour in chicken broth and milk.
Whisk constantly to prevent lumps.
Cook until sauce thickens into a creamy consistency.
Remove from heat and fold in chopped chicken.
Season with salt, pepper, nutmeg, and thyme.
Refrigerate mixture for 1-2 hours until firm.
Shaping and Breading
Shape chilled mixture into cylinders or desired shape.
Dip croquettes in beaten eggs.
Roll croquettes in seasoned breadcrumbs until fully coated.
Frying to Perfection
Heat oil to 350°F (175°C) in a pan.
Test oil with a breadcrumb; it should sizzle.
Fry croquettes in batches for 3-4 minutes.
Remove croquettes and drain on paper towels.