This true story is inspired by last week’s celebration of National Cheesecake Day: A year ago when the economy was in the tank, I read in Nation’s Restaurant News that just about the only eating place in the country making money was The Cheesecake Factory. As a rule I don’t like chain restaurants, and I was perplexed. A surprising thing happened: In my course of checking out the franchise, which turned into a story for National Public Radio, I fell in love with the miso salmon there. It is buttery, luxurious, and mouthwatering: proof of the chain’s popularity on a plate. My colleague Michael Ruhlman teased me, but eventually even he had to admit that the dish rocks. I can’t tell you how to make it because the official recipe has never been published. I can tell you that sometimes it’s good to challenge your preconceptions about food and restaurants. Ever happen to you?