1. Heat the oven to 400°F and arrange a rack in the middle. Coat a 9-inch pie dish with cooking spray.
2. Take out the three HomeBurger OR Nature Burger patties, and start crushing them up to be a bowl of burger meat!
3. In a frying pan over medium heat, warm the oil. Add the onion and a sprinkle of salt and cook until golden brown, about 5 minutes. Add the patty meat you just grounded up along with a big pinch of salt and some black pepper. Raise the heat to medium high and cook, stirring occasionally, until the meat is browned, about 5 minutes. If there is any fat, make sure to drain it out of the beef! Transfer the mixture to the pie dish and spread in an even layer. Set aside.
4. In a food processor, pulse together the flour, baking powder, sugar, and measured salt. Add the butter and pulse until the mixture looks like coarse breadcrumbs. Add the milk and eggs and pulse until the mixture is blended. Pour this batter over the meat in the pie dish. Sprinkle the top with the cheese.
5. Bake until golden brown and set, and a knife inserted in the center comes out clean, about 25 minutes.