Melt butter in a pan over medium heat and stir in flour to make a roux.
Gradually add milk while stirring until smooth and thickened.
Add cheddar and mozzarella cheese and mix until melted.
Stir in cooked macaroni, salt, and black pepper until fully combined.
Transfer mixture to a tray and refrigerate for 1 hour until firm.
Scoop and shape into small bite-sized balls.
Dip each ball into beaten eggs, then coat with breadcrumbs.
Heat oil in a deep pan over medium heat.
Fry the bites in batches until golden brown and crispy.
Remove with a slotted spoon and drain on paper towels.
