Meghan Markle's recent visit to The Falkland Arms in Great Tew, Oxfordshire, drew blunt commentary from the Daily Mirror's royal editor Russell Myers, who joked that her choice of sauce with fish and chips was a sacrilege.

Photos showed Markle enjoying the pub meal with her friend Kelly McKee Zajfen during her UK trip with the Sussex family. The images of the duchess tucking into one of Britain's most beloved dishes in a traditional Cotswolds pub were always going to generate strong opinions, and so it proved.

Myers's verdict was delivered with a wink, but it touched a nerve. The correct accompaniment to fish and chips is a matter of fierce regional pride, with vinegar, tartare sauce, gravy and curry sauce all commanding loyal followings. The suggestion that Markle got it wrong prompted a predictable wave of amusement and mock outrage, and a debate that briefly overshadowed more serious royal stories.

The pub visit was part of a wider UK trip for the Sussex family, during which every public appearance has been scrutinised. Markle's choice of a low-key country pub, rather than a high-end restaurant, was seen by supporters as a genuine attempt to enjoy normal British life, and the photographs showed her relaxed and smiling.

The Falkland Arms, in the picturesque village of Great Tew, is exactly the kind of establishment that trades on its traditional charm, all low beams and local ale. A visit from a member of the royal family, however unofficial, is the kind of publicity money cannot buy, and the pub has been basking in the attention.

In the end, the great sauce debate may be the lightest story of the Sussexes' trip. But in Britain, few things are taken more seriously than how you eat your chips, and the duchess has learned that even a quiet pub lunch comes with a side order of controversy.

The Sussexes' UK visits are always closely watched, and their choice of low-key venues has been noted by royal commentators. The Falkland Arms is a classic English country pub, the kind of place that features on chocolate-box calendars, and the photographs of Markle enjoying her meal played well with supporters who see the couple as down-to-earth. Myers, one of the most experienced royal correspondents in the business, delivered his verdict with the practised mischief of a man who knows exactly how seriously Britain takes its food traditions. It was, by any measure, a memorable lunch, even if the sauce remains a matter of fierce debate.