Prepare the patty by combining the ground beef, breadcrumbs, mustard powder, 1 teaspoon beef powder, onion powder, garlic powder, 1/8 teaspoon ground black pepper, and 1/2 teaspoon salt in a bowl. Mix all the ingredients together. Form the meat mixture into patties.
Heat the cooking oil in a pan.
Once the oil becomes hot, pan-fry the burger patties in medium heat for 3 to 5 minutes per side depending on the thickness. Set aside.
Prepare the gravy by melting the butter in a clean saucepan.
Once the butter becomes hot, put-in the sliced mushrooms. Cook for 1 minute.
Add the flour. Stir until the flour absorbs the butter and a lump is formed.
Pour-in the water and 1 1/2 teaspoons beef powder. Stir well to distribute the distribute the ingredients well. Continue to cook until the gravy reaches the desired thickness. Add more water if the gravy is too thick. Add salt and pepper to taste.
Arrange the cooked patties in a serving plate. Pour the beef and mushroom gravy on top.
Serve. Share and enjoy!