He came, finished up the food and hesitantly let me pet him, before heading off. But he was back the next night, sitting patiently on the patio stones. I brought him another bowl of food which he gobbled right down. Since then he's shown up at least every other night, staying longer and letting me pet him more.
I decided he needed a name, and that he looked a little like a Stan. Dave didn't like that though... he called him Relic (yes... after the Beachcombers....) So... Relic he is.
He was coming around so often, I made him a little make-shift shelter out of a rubbermaid tub and an old flannel sheet). Soon after, Relic started coming during the day.
He always wanders off at some point, but he's usually back the next day, or the night after...
As much as I'd like to bring him in, I can't do it until he's seen a vet (and he's not fond of being picked up, so getting him in a carrier at the moment isn't going to happen.) And the fact that he's an intact adult means he might not be an ideal house cat anyway... even after neutering, he may still have a tendency to spray.
But for now, he can be my garden cat. He can come for food, and a safe place to sleep, and come the cold weather, we'll see if he trusts us enough to let us help him to a better situation.