ALthough I remember this story as being mature but not explicit content wise, I'll put it below the cut, just in case.
It was a J2 fic where Jensen has fire powers/ pyrokinesis and difficulty controlling them so he lives in the middle of nowhere to protect everyone. His house is completely fireproofed except for his garden. One day, his usual gardener can't come so Jared is the replacement. Luckily he is fireproof (idk how) so Jensen can't hurt him. Attraction develops. Jared brings him a flower every day but Jensen always burns them and secretly saves the ashes in a glass jar. All of this is a lot for Jensen because he's been too scared to touch anyone for fear of hurting them.
I remember a lot of details except for the title, of course, so any help would be greatly appreciated.