It might very well be the best burger you’ve ever had.

But it’s not listed on the menu. At least not yet.

The only way you can try the sublime double-patty creation at Bird Dog in downtown Palo Alto is to know about it and ask for it.

So for those of you reading this, go for it. You won’t regret whispering this order to your server.

What makes this burger so special?

Chef-Partner Robbie Wilson makes everything in house. We’re talking the sturdy yet yielding bun, a cross between a Parker House roll and a traditional one, which gets sprinkled with a flourish of burnt leek ash. There are the double patties, a mix of brisket and short rib, for big beefy flavor and juicy richness. There’s the spicy chili crunch with Chinese mustard that gives it all a surprise hit of moderate heat at the finish. There’s the flourish of shiitakes, fermented for two months, that explode with umami. And there’s the fact that Wilson even went so far to make his own American cheese, which gets splendidly gooey all over the meat.

The result is a burger that is a savory sensation — its meatiness accentuated and amplified.

I had a chance to try it on the house when I dined at lunch time last week with one of my editors, who picked up the tab for everything else we pigged out on.

At lunch time, the burger will go for about $18. Wilson said he’s not serving it with fries, but is thinking of maybe a more unusual side instead. At dinner time, the burger can be ordered at the bar for about $26. Lest you think that steep, know that it will come with a glass of very good wine included in the price.

Only a few burgers will be available each day. So once they are gone, you’re out of luck. But Wilson says they can be reserved ahead of time at lunch. And come later this summer, maybe July or so, he expects the burger to be officially on the menu.

If a burger is not what you’re in the mood for, there’s plenty more to like at Bird Dog.

Slivers of clean, creamy kanpachi ($18) get a drizzle of dashi vinegar, as well as a grating of horseradish and Buddha’s Hand. Again, there’s the wonderful savoriness to the dish, as well as a refreshing brightness.

Mentaiko ($14) is the butter spaghetti of your dreams. Preserved egg and nori give the dish much more depth, as does the cultured butter. The supple toothsome noodles are tossed in buttery bliss. It’s haute comfort food.

I love hamachi collar ($22), even if you have to work for it. Use chopsticks to dig out every morsel of the succulent flesh that’s imbued with smokiness from the grill. A whisper of nuoc cham, the Vietnamese dipping sauce, and some cooked stalks of chrysanthemum greens, give it all a lovely Asian-inflected touch.

Pastry Chef Serena Chow offers up the cutest little donuts ($10) for dessert. How small are these? I could probably fit all three — chocolate, sugar-dipped and glazed — in the palm of my hand and still have space leftover. As Wilson says, sometimes one regular-sized donut just feels like too much. The chocolate donut comes with a scoop of espresso ice cream that dwarfs it. The tiny donuts are way too fun. I especially liked how the chocolate one was not very sweet, letting the bitter-earthy flavor of the chocolate shine through.

The Citrus Parfait ($9) is wonderful with its circles of moist lemon yogurt cake layered with cream cheese mousse and blood orange sorbet. It’s like a much more intense version of a 50-50 ice cream bar.

If you haven’t been to Bird Dog in awhile, time’s a wasting. Especially when burgers are now available for those in the know.

And: More Bird Dog