Since umami is the “fifth taste” (also referred to as savoriness), we’ve listed our top five reasons we’re excited about the now-open, much-anticipated L.A. burger chain of the same name.1. The Union Street space resembles an Asian-influenced haven, with a samurai sword upon entry, reclaimed shingle wall, circular wooden bar, and bamboo accents.2. Owner Adam Fleischman has seared, stamped, and sauced tasty goodness into every component to create a burger that just might be the city’s best.3. The namesake stack: ground-on-the-premises patty, shiitake mushroom, caramelized onions, roasted tomato, a Parmesan crisp, and umami ketchup (the special sauce to end special sauces).4. The SF-exclusive bacon-wrapped scallop burger, topped with crispy pork belly, sweet chili sauce, and yuzu-garlic aioli.5. Mostly local beer and wine for pairing (servers are happy to help).Now that’s in good taste.Umami Burger Union, 2184 Union Street, at Fillmore Street (415-440-8626 or umamiburger.com).