When Shane Jones describes National Party frontbencher Paul Goldsmith as being like a dentist, he means it in the nicest possible way.
The New Zealand First Cabinet minister was describing how Goldsmith would get very close to hitting a nerve with the clinical interrogations of Jones in Parliament's Question Time over the Provincial Growth Fund.
It earned Goldsmith respect and a promotion three weeks ago from his good friend and running mate, leader Simon Bridges.
"I used to have a bit of fun with Goldie," Jones told Newstalk ZB last week. "His approach is that of dentist. He is drilling fillings and he is getting close to a root canal."
It was that effective needling of Jones that made him the obvious choice for promotion to finance spokesman when Amy Adams decided to step aside.
Goldsmith will be facing Finance Minister Grant Robertson who moved almost seamlessly from a backroom Beehive political operative to politician.
Goldsmith says he knows more about running a small business than Robertson, having run one himself – although it must be said it was a business writing biographies about successful businessmen commissioned by successful businessmen.
He has also written the definitive history of taxation in New Zealand.
But Goldsmith is more interesting than his fascination in tax history would suggest.
He is a taekwondo expert (2nd dan black belt), a Treaty of Waitangi aficionado, a runner and a pianist.
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He grew up in Mt Roskill but attended Auckland Grammar as an out of zone boy because his father taught maths there.
His mother, a palliative care nurse, and father made him take weekly piano lessons in Titirangi, for which he is very grateful.
It's what he does to relax when he get backs home to Epsom where he lives with wife Melissa Wilson and four children.
"We all like to have a bit of beauty in our lives and the piano is one area where I always find a bit of rest and pleasure."
Goldsmith obliges the Herald's request to demonstrate on the grand piano in Parliament's Grand Hall, and chooses a little bit of Schubert and Elton John's Rocket Man.
Goldsmith was first elected to Parliament in 2011 although he worked there as a press secretary to three cabinet ministers: John Banks in Police, Simon Upton in Environment and Phil Goff in Foreign Affairs.
He did his MA in history under the tutelage of a renowned historian, the late Judith Binney, and his first job was at the Waitangi Tribunal putting together evidence for historical claims.
"I went from there to work for John Banks which was regarded as a bit of a sensation at the tribunal. It was a scandal."
Each of the ministers had given him a good education in politics, he said.
"They were all very different in their own way. Banksie of course was out there most of the time but was very good at crystallising ideas in a very simple pithy phrase.
"Simon Upton was much more policy [focused], a very intelligent, very thoughtful politician and Phil was high energy. If he wasn't on the TV news in two or three days you'd get into a blind panic and be up til two or three o'clock every night."
Goldsmith wrote a biography of Banks, the first of many non-fiction books he has written.
He was commissioned to write a book by Alan Gibbs about a Maori chief, Te Hemara Tauhia, who is buried on his Kaipara sculpture park and from 2003 was a full-time author.
"I did one of Douglas Myers and his family; I did one on the history of Fletchers, the company, a guy called Richard Izard, a businessman, Don Brash, Bill Gallagher, Alan Gibbs, I think there were about 12."
Speaking about his approach to Shane Jones in Parliament over the past 18 months, he said the aim was to ask basic questions about what he was trying achieve and where the $3 billion was going and to see where the questions led.
"Of course with Jones it led in all sorts of strange directions because he didn't seem to have very good answers most of the time. Somebody described him like a pot of porridge on the stove that just bubbles over all the time, so there is a lot of material to work with.
"So there's an element of trying to get the answers there then fundamentally putting them under pressure and seeing how they react and revealing their shortcomings, and I went about that in a methodical way."
A huge amount of research went into it, asking parliament questions and Official Information Act requests.
"Out of every 500 answers you got about half a dozen that required further research and led on to something. There was a lot of hard work involved."
Will he be taking the same approach with Grant Robertson?
"I expect him to be more disciplined and so I think it will be harder in that respect so it just a question of testing him."
Goldsmith is a dry. He has a dry sense of humour and is seen as perhaps the most tinder dry member of the caucus economically – essentially a disciple of Rogernomics who believes in a shrinking role for the state over increasing Government intervention.
He acknowledges the reputation although deflects it by saying it is not unusual for National finance spokesmen to be on the "more cautious side of the spending ledger."
"I'll be advocating policies that are good for the economy and I'll be advocating careful spending and an absolute focus on getting results for that spending, which is the basic stuff you'd expect a National Party finance spokesman to be doing."
The definition of a successful Finance Minister depended on the circumstances of the country at the time.
"Roger Douglas did a great job at a time that we needed radical reform. You wouldn't necessarily want a radical reformer at a different period.
"Whereas I think Bill English did a great job steering the country through a very difficult period and consistently taking up back from a period of massive deficit to surplus and good growth."
Goldsmith is working on his speech for the National Party conference in Christchurch this weekend which he promises will be punchy, not long-winded.
He is also limbering up for his encounters with Robertson at Question Time which he regards as one of the most important parts of New Zealand's democracy.
"The ministers are all there on a regular basis, and they have to account for their actions and what they've said and they get tested.
"I didn't enjoy it as a minister but I enjoy it in opposition because it gives you an opportunity to see what they are made of."