Prepare Potatoes: Cut the potatoes and blanch in 1L of boiling water with 10g of salt for 5 minutes.
Brown the Ground Beef: In a pan, heat duck fat and add ground beef. Season with salt and pepper, and cook until browned.
Prepare Onions and Garlic: Finely chop the onions and garlic. In another pan, cook them until they start to sweat.
Mix Ingredients: Combine the beef, potatoes, onions, garlic, and green onions in a large bowl.
Prepare Eggs: Whisk 6 eggs with a little salt and pepper.
Assemble the Casserole: In a greased baking dish, layer the beef and potato mixture. Pour the whisked eggs over the top and sprinkle with grated cheese.
Bake: Cover and cook on the stove for about 2 minutes. Then, transfer to a preheated oven and bake under the grill for 3 minutes or until golden brown.
Serve: Let it cool for 3 minutes before serving. Enjoy a hearty breakfast casserole perfect for winter mornings.