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.

8 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
16cups 3.79l 3785ml 6.66pint 252tbsp 757tsp mushrooms	slice
8tbsp 0.12l 120ml 24tsp 0.507cup 0.211pint butter
8tbsp 0.12l 120ml 24tsp 0.507cup 0.211pint flour
1500ml 1 ¹⁄₂l 100tbsp 300tsp 6.34cup 2.64pint beef broth
4tbsp 0.06l 60ml 12tsp 0.254cup 0.106pint marmite
burgers
2000g 2kg 4.41lb 70.5oz minced beef	mix	form into 16 patties	brown	remove to plate
4tbsp 0.06l 60ml 12tsp 0.254cup 0.106pint worcestershire sauce
4tbsp 0.06l 60ml 12tsp 0.254cup 0.106pint garlic powder
salt
pepper
4tbsp 0.06l 60ml 12tsp 0.254cup 0.106pint onion powder
4 egg
oil
16 slices of white bread