It is Friday afternoon and Jack Chambers is sitting in his spacious ground-floor office in the Department of Finance.  Three days have passed since Chambers delivered his first budget speech as minister for finance and, despite the huge €10.5 billion package that he unveiled in tandem with public expenditure minister Paschal Donohoe, the world, and Chambers’ own schedule, is beginning to move on. There is the Fianna Fáil president’s dinner to attend. When he appeared last year, he was a junior minister, albeit one with a ticket to attend cabinet. Now, he returns as the finance minister, Fianna Fáil’s deputy…