HAVE you ever been curious about the secret ingredients in your tasty restaurant meal?

Well turns out you may not want to dig too deep to uncover the secret. An expensive French restaurant in Tokyo is serving up fancy meals with a key ingredient: dirt.

It's a special black soil from Kanuma, Tochigi Prefecture, and it has been tested for safety, according to Japanese news site Rocketnews42. But it's still dirt, and usually chefs work to keep it out of meals.

But not Toshio Tanabe, chef at the restaurant Not Ne Quittez Pas, who has created a full dirt-infused menu after winning a high-profile cooking contest with his dirt sauce.

His menu includes locally-sourced produce and "minerals of the sea and minerals of the land".

Those visiting his restaurant will have to fork out $110 to be served a first course of potato starch and dirt soup topped with black truffle in a shot glass.

Second course? You guessed it – more dirt, this time in a vegetable salad including eggplant, tomato and turnips. The dirt is included in the dressing, which also contains ground popcorn.

The main course is oriental clams with a top layer of sediment, with a dirt risotto and sautéed sea bass and burdock root. And what better way to finish it all off than with dirt ice cream, and a dirt mint-tea with the appearance of muddy water?

While eating dirt isn't new, crafting an entire menu out of it is.

But it was a hit - a reporter who braved the meals said there was no detectable dirt taste: "The food tasted so little of the earthiness I was expecting that I'd kind of forgotten about that ingredient".

