This is an excerpt from the New York Times:

President-Elect Trump: “General Mattis is a strong, highly dignified man. I met with him at length and I asked him that question. I said, what do you think of waterboarding? He said — I was surprised — he said, ‘I’ve never found it to be useful.’ He said, ‘I’ve always found, give me a pack of cigarettes and a couple of beers and I do better with that than I do with torture.’
“And I was very impressed by that answer. I was surprised, because he’s known as being like the toughest guy. And when he said that, I’m not saying it changed my mind. Look, we have people that are chopping off heads and drowning people in steel cages and we’re not allowed to waterboard. But I’ll tell you what, I was impressed by that answer. It certainly does not — it’s not going to make the kind of a difference that maybe a lot of people think. If it’s so important to the American people, I would go for it. I would be guided by that. But General Mattis found it to be very less important, much less important than I thought he would say. I thought he would say — you know he’s known as Mad Dog Mattis, right? Mad Dog for a reason. I thought he’d say ‘It’s phenomenal, don’t lose it.’ He actually said, ‘No, give me some cigarettes and some drinks, and we’ll do better.’”

see the entire New York Times interview here. it’s really good.