They don't take bookings at Saan. Instead, you turn up, find it full and give them your cellphone number. They call you when a table is ready.
I presume the idea is to create a sense of unattainability that, among the reef-fish diners of Ponsonby, is hard to distinguish from hysteria. But it's really a booking system designed with the establishment, not the customer, in mind and I don't care for it. If New York's Momofuku Ko can have a reservation system, all these places that "operate a walk-in policy" can, too.
Playing hard to get can backfire, anyway. Having declined the long wait once, we scored a table by turning up at 5.30pm on a Tuesday (it would have been a challenge at 7pm). By that time my taste buds were aching and my expectations were high, so perhaps mild disappointment was inevitable.
Saan, the new venture by the people behind the excellent Cafe Hanoi in Britomart, focuses on the cuisine of northern Thailand, so it's not the place to go if you're after moneybags, pad thai and green curry chicken. Isaan (northeastern) food has Khmer and Laotian influences; the food from the former Lan Na kingdom (if you have been to Chiang Mai, you probably ate it) is only mildly spicy and big on deep frying.