Preheat the oven to 350°F (175°C).

In a sizable bowl, combine the ground beef, bread crumbs, minced onion, beaten eggs, salt, and black pepper. Mix the ingredients thoroughly until evenly blended. Lay a piece of wax paper on a flat surface and pat the meat mixture into a 14x18-inch rectangle.

Evenly distribute the shredded Cheddar cheese over the meat, leaving a ¾-inch border along the edges. Starting from one short end, roll up the meat in a jelly-roll fashion to enclose the cheese, forming a pinwheel loaf. Firmly press the ends of the loaf to seal in the filling. Transfer the meatloaf to a 10x15-inch baking dish.

Bake in the preheated oven for approximately 1 hour, or until an instant-read thermometer inserted into the center registers at least 160°F (70°C), indicating the meatloaf is fully cooked.

Let rest briefly before serving.