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.

9 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
18cups 4.26l 4259ml 7.49pint 284tbsp 852tsp mushrooms	slice
9tbsp 0.135l 135ml 27tsp 0.571cup 0.238pint butter
9tbsp 0.135l 135ml 27tsp 0.571cup 0.238pint flour
1687 ¹⁄₂ml 1 ¹¹⁄₁₆l 112 ¹⁄₂tbsp 337 ¹⁄₂tsp 7.13cup 2.97pint beef broth
4 ¹⁄₂tbsp 0.068l 67 ¹⁄₂ml 13 ¹⁄₂tsp 0.285cup 0.119pint marmite
burgers
2250g 2 ¹⁄₄kg 4.96lb 79.4oz minced beef	mix	form into 18 patties	brown	remove to plate
4 ¹⁄₂tbsp 0.068l 67 ¹⁄₂ml 13 ¹⁄₂tsp 0.285cup 0.119pint worcestershire sauce
4 ¹⁄₂tbsp 0.068l 67 ¹⁄₂ml 13 ¹⁄₂tsp 0.285cup 0.119pint garlic powder
salt
pepper
4 ¹⁄₂tbsp 0.068l 67 ¹⁄₂ml 13 ¹⁄₂tsp 0.285cup 0.119pint onion powder
4 ¹⁄₂ egg
oil
18 slices of white bread