Hot Hamburger Sandwich - Cooking like a Boss

Traditional Canadian comfort food. It's a burger on top of a slice of bread covered in gravy. Much nicer than it deserves to be! Serve with garden peas and chips.

2 medium onions	dice	fry in burger pan until golden	fry until mushrooms golden	melt	stir in	stir in	season	return burgers to pan	cover and simmer until cooked through	top
oil
4cups 0.946l 946ml 1.67pint 63.1tbsp 189tsp mushrooms	slice
2tbsp 0.03l 30ml 6tsp 0.127cup 0.053pint butter
2tbsp 0.03l 30ml 6tsp 0.127cup 0.053pint flour
375ml ³⁄₈l 25tbsp 75tsp 1.59cup 0.66pint beef broth
1tbsp 0.015l 15ml 3tsp 0.063cup 0.026pint marmite
burgers
500g ¹⁄₂kg 1.1lb 17.6oz minced beef	mix	form into 4 patties	brown	remove to plate
1tbsp 0.015l 15ml 3tsp 0.063cup 0.026pint worcestershire sauce
1tbsp 0.015l 15ml 3tsp 0.063cup 0.026pint garlic powder
salt
pepper
1tbsp 0.015l 15ml 3tsp 0.063cup 0.026pint onion powder
1 egg
oil
4 slices of white bread