My "Umami" Burger

I read in the November GQ magazine that the Umami burger has been voted best hamburger in Los Angeles... This is my version of this Umami burger which is supposed to evoke the 5th taste after sweet, sour, salty and bitter...

The burger patties are made from ground beef mixed with bits of crunchy bacon, and marinated in a "secret umami" sauce (in this case, I used Vietnamese fish sauce mixed with some sugar and vinegar) and grilled to medium. The toppings are caramelized onions, sauteed mushrooms, lettuce and oven baked and herbed cherry tomatoes with melted gruyere cheese. The wholewheat buns are spread with garlic butter and quickly grilled. To serve with French fries... Amazing tastes, juicy, crunchy, soft, and that 5th taste...