01 -
Heat a heavy skillet over medium heat. Add ground beef and break it up using a sturdy spoon. When halfway browned, add chopped onion and minced garlic. Stir constantly until beef is fully cooked and onions become translucent, approximately 8 minutes.
02 -
Remove pan from heat. Stir in ketchup, yellow mustard, salt, and pepper. Mix thoroughly and allow the filling to cool for at least 5 minutes to prevent scrambling the batter in the next step.
03 -
Lightly grease a 23-centimeter (9-inch) pie dish with oil or butter. Spread the cooled beef mixture evenly across the base, pressing lightly without compacting. Evenly sprinkle shredded cheddar cheese over the beef layer.
04 -
In a large bowl, whisk together whole milk, Bisquick, and eggs until smooth and free of lumps. Pour the batter gently over the cheese and beef, allowing it to settle evenly.
05 -
Place the dish into an oven preheated to 200°C (400°F). Bake for 25 to 30 minutes until the top is puffed and golden brown and the center is set without wobble. Remove and let rest for 5 to 10 minutes before slicing.