Preheat the oven to 440 degrees.

Make the pot roast: Evenly sprinkle the chopped onion into a large roasting pan or a deep baking dish. With a knife, cut five slits throughout the beef. Tuck in a garlic clove into each slit. Liberally season the beef with salt and pepper. Place the beef into the roasting pan. Drizzle the oil into the pan over the onions. Cook the beef for about 15 minutes and transfer the roasting pan out of the oven. Lower the oven temperature to 375 degrees. Pour ¾ cup water into the pan and transfer the roasting pan back into the oven. Roast for another hour and 30 minutes until the beef is cooked through and browned. Set the roast aside and save all the pan juices. Once the pot roast is cool enough to handle, chop it into 1 inch cubes.

Prepare the potatoes: Place the potatoes in a large pot and cover with cold water. Bring the water to a boil over medium-high heat and cook the potatoes for about 30 minutes until fork tender. Drain the potatoes and transfer to a cutting board. Once the potatoes are cool enough to handle, peel and chop them into 1 inch cubes.

Make the pot roast sauce: In a small pot, heat the leftover roasting pan juices with the worcestershire sauce, over medium-high heat. In a small bowl, mix the cornstarch and water until combined. Once the sauce boils, add in the cornstarch mixture and stir until the sauce thickens, about 1 to 3 minutes. Set aside.

Make the hash: Place a large saucepan over medium to medium-heat. Once the pan is hot, add 2 tablespoons of oil and place the onion on the pan. Cook the onions until they have softened, about 5 minutes. Add the potatoes into the pan and saute until they have browned, another 5 minutes. Add the chopped pot roast, salt, pepper and half of the pot roast sauce. Mix well and let the mixture cook for another 5 minutes, until all the components are coated with the sauce. Add more sauce if needed.

Fry the eggs: Place a medium sauce pan over medium heat. Place 1 to 3 tablespoon of vegetable oil in the pan. Crack one egg into a bowl and pour it into the pan, continue with the remaining 3 eggs. Season the eggs with salt. Fry the eggs until the bottom of the eggs have browned and the egg whites have set.

To serve, pour about two scoops of hash onto a plate and place one fried egg on top for each serving.