He believes it is the fastest time in which a chef in America has been awarded a star and said he had no idea he was being judged.
The challenge is to keep the star because they can be taken off you.
"It's pretty scary.
"They keep coming back to see if you are still worthy of the rating or if you have done something different to rate you moving up or if everything just fell off and you don't deserve anything."
He was sitting in the restaurant on Saturday afternoon while staff were prepping for the evening offerings; the special was fried bone marrow with orange sauce, caviar and kina.
The quote of the day on the wall for staff was by Henry Ford: "You can't build a reputation on what you are going to do."
He describes The Musket Room as a New Zealand restaurant and about 60 per cent of the wines are from New Zealand, overseen by sommelier Cameron Douglas from his Auckland home patch of Henderson.
Mr Lambert says the Michelin star has been enormously helpful because international visitors seek him out.
He does the same when he travels and is planning to visit a three-star restaurant in France this year.
He has been happy to have some famous faces through the door since it opened a year ago, including actor Sam Neill, actress Olivia Wilde and All Black Liam Messam when he was in the country to promote the All Blacks vs Eagles game in Chicago in November.
One of the biggest thrills, though, has been able to cook for US chef legends such as Top Chef's Tom Colicchio and Wylie Dufresne, who runs Mr Lambert's favourite restaurant, wd-50.
Ultimately, Mr Lambert would like to open a restaurant in New Zealand. "A lot of people just think [of New Zealand] as Peter Jackson and Hobbits and then they try the wine and the food and everything's going screamingly well."
To read more from Audrey Young go here.
