01 -
Preheat the oven to 400°F. Grease a 9-inch glass pie plate with vegetable oil.
02 -
Heat oil in a large skillet over medium heat and cook the chopped onion until soft, about 3 minutes.
03 -
Add ground beef to the skillet, breaking apart with a spatula. Cook until browned, about 10 minutes. Drain excess fat and season with salt, black pepper, and garlic powder if desired.
04 -
Spread the cooked beef mixture evenly in the prepared pie plate. Sprinkle grated Cheddar cheese over the beef layer.
05 -
In a small bowl, whisk together Bisquick mix (or all-purpose flour), milk, and eggs. Pour the mixture over the beef and cheese layers in the pie plate.
06 -
Bake for 20 to 25 minutes, or until a knife inserted in the center comes out clean.
07 -
Serve warm and enjoy this comforting slice of cheeseburger pie.