01 -
Preheat oven to 400°F. Lightly grease a 9-inch glass pie plate with vegetable oil.
02 -
Heat a small amount of oil in a large skillet over medium heat. Sauté chopped onion until softened, about 3 minutes.
03 -
Add ground beef to the skillet and cook, breaking apart with a spatula, until browned, approximately 10 minutes. Drain excess fat.
04 -
Season the beef and onion mixture with salt, ground black pepper, and garlic powder if desired. Stir to combine evenly.
05 -
Transfer the seasoned beef and onion mixture evenly into the prepared pie plate. Sprinkle grated Cheddar cheese over the meat layer.
06 -
In a bowl, whisk together Bisquick mix or flour, whole milk, and eggs until fully combined.
07 -
Pour batter evenly over the meat and cheese layers. Bake for 20 to 25 minutes or until a knife inserted in the center comes out clean.
08 -
Allow the dish to cool slightly before slicing. Serve warm.