Begin by heating a large skillet over medium heat and adding the ground beef. Cook for about 5-7 minutes, breaking it apart until browned. Drain excess fat.

Add diced onions, Worcestershire sauce, salt, and pepper to the skillet. If desired, incorporate ketchup and mustard. Cook for an additional 2-3 minutes.

Spread the meat and onion mixture evenly in a greased pie plate. Sprinkle shredded cheddar cheese over the top. Preheat oven to 375°F (190°C).

In a mixing bowl, combine the biscuit mix, milk, and egg. Stir just until combined, avoiding overmixing.

Drop dollops of the biscuit dough over the cheese layer. Aim for a rustic look with small sections.

Bake in the preheated oven for 20-25 minutes until the topping is puffed and golden brown.

Remove from the oven and let it rest for about 5 minutes. This allows layers to set for easier slicing.

Serve and enjoy, optionally garnished with chopped fresh parsley or chives and with extra ketchup or mustard.