Umami Burger. Apparently celebrities like it.

Umami Burger Drawing
There's apparently a lot of these Umami Burger restaurants in Los Angeles and celebrities like them. The burgers themselves, out of sheer speculation, are probably the same as any other burger joint that spends a little more on better quality beef. The key component is the Umami sauce.

Umami is essentially the fifth taste bud sensation we can taste, once hidden away during our elementary learnings of youth. It's description is that of a "savory" nature... like a nice, meaty, broth-like yum. The most classic example is the shiitake mushroom. It's not sweet, sour, salty or bitter. It's got this... other flavor... this umami flavor.

Based on that, I can only guess that this special sauce incorporates a lot of foods rich in umami flavors. If I were to make this sauce, it'd probably be a mix of extra ripe tomatoes, shiitake mushrooms and some kind of beefy bouillon powder. Maybe replace the tomatoes with something more like a ketchup, but homemade of course.

Speaking of special ketchup, have you ever tried curry powder in ketchup? Pretty tasty.

Related Link: Google Trending "Umami Burger"