Preheat your oven to 400°F (200°C).
In a large skillet, brown the ground beef over medium heat, breaking it apart with a wooden spoon.
Add the chopped onion to the skillet and cook until translucent, about 5 minutes.
Stir in garlic powder, salt, and pepper to taste, then remove from heat.
In a separate bowl, whisk together the milk, eggs, flour, and baking powder until smooth.
Fold in the browned beef mixture and shredded cheese until thoroughly combined.
Pour the mixture into a greased pie dish and smooth the top.
Bake in the preheated oven for 30-35 minutes or until set and golden on top.
Remove from the oven and let it cool for about 10 minutes before slicing.