Is “Know how to cook leeks”an idiom? What does “Read “Hamlet” and know how to cook leeks” mean?

There was the following sentence in New York Times’ article (February 28) titled “What you learn at 40s.”:

"Victor Hugo supposedly called 40 “the old age of youth.” - - The conventional wisdom is that you’re still reasonably young, but that everything is declining: health, fertility, the certainty that you will one day read “Hamlet” and know how to cook leeks. Among my peers there’s a now-or-never mood: We still have time for a second act, but we’d better get moving on it." http://www.nytimes.com/2014/03/01/opinion/sunday/what-you-learn-in-your-40s.html?hp&rref=opinion&_r=0

What does the line -“Read Hamlet and know how to cook leeks” mean? Is “Know how to cook leeks” an idiom, for instance, to mean to get 'the worldly knowledge'?

Readers English Japanese Dictionary at hand carries “eat the leek” and “not worth a leek” as idioms, but don’t include “know how to cook leeks.”

Solution 1:

I'm pretty sure there’s no connection intended between the literary and culinary achievements. I think you are misparsing this as

the certainty that you will someday read Hamlet and [as a result] know how to cook leeks

when in fact it is supposed to be parsed as

the certainty that you will someday read Hamlet and [that you will also someday] know how to cook leeks.

Solution 2:

Once you click on the link and read the article it's pretty clear why the author chose to combine the reading of Hamlet with the knowledge of cooking leeks.

Entering middle age in Paris — the world’s epicenter of existentialism — isn’t terribly helpful. With their signature blend of subtlety and pessimism, the French carve up midlife into the “crisis of the 40s,” the “crisis of the 50s” and the “noonday demon” (described by one French writer as “when a man in his 50s falls in love with the babysitter”).

Victor Hugo supposedly called 40 “the old age of youth.” In Paris, it’s when waiters start calling you “Madame” without an ironic wink. [...]

The American author is celebrating her 44th birthday in Paris, the capital of France. France is famous for its fashion, its art, and for its cuisine. One of the most famous dishes being the classic Vichyssoise, which is a fancy title for 'cold leek and potato soup'. A dish that the writer may have tasted in many a restaurant as a young woman but had never cooked for herself or her family. How does a seemingly tough and bland vegetable produce such a delicate and flavoursome soup? Is probably a question many young women have asked themselves when faced with the vegetable for the first time.

The author argues that the certainty that one day we will be confident enough to cook this long stalk and read Hamlet for pleasure, rather than for school homework declines as we pass our mid-forties. Time is running out, but it's not too late.

EDIT Thanks to @LessPop_MoreFizz for the precision.

Solution 3:

I think the author could have used any expression that would be interpreted as “something I'll get around to one day...” (for example, making a quilt, teaching yourself how to play the guitar, or mastering a flip turn in the swimming pool – any generic “unfinished business” activity). In the song Time, Pink Floyd expressed talked about half-written poems or outlines, singing:

Every year is getting shorter, never seem to find the time
Plans that either come to naught or half a page of scribbled lines

It doesn't appear to be an established idiom. I had never heard it before. When I Googled "know how to cook leeks", I found all of 28 hits on the internet; Google books only returned six hits for "how to cook leeks".