I've had this little ficlet tumbling around my brain for a while and had to get it out.
Set immediately after "The End of the World".
The Doctor had forgotten just how much he loved chips. It was a lovely human delicacy: deep fried potato wedges slathered in salt and vinegar. Practically no real nutritional value, yet there was something so intrinsically comforting about them.
Rose had wanted them almost as soon as they had stepped out of the TARDIS. She watched the remains of her planet float aimlessly around just a short while ago, burned up by its own sun. The Doctor wished his own planet would have been capable of such an end, as that would have meant it had survived long enough. He told Rose about the war, that his people had lost and now he was the last of his kind.
She popped another chip in her mouth, looking around thoughtfully at the park they were sitting in. Earth was still here, and she now knew how many millions of years it will survive. Humans will spread out amongst the stars, and everyone would have at one point at least heard of planet Earth.
The Doctor finished up the last chip that was in his bag and crumpled up the paper, and laughed when Rose had placed her empty bag in his hands as well.
"Gallifrey." He said, without any preamble as he crumpled both bags together into a ball and lobbed it into a nearby bin.
"What?" She asked around her last chip.
"You asked me earlier where I'm from." He shrugged, trying to forget the horrible argument they had when she had asked before.
"Gala… uh…" She started and he grinned.
"Gallifrey." He gently corrected for her.
"Gallifrey. That's such a beautiful name." She smiled. "What was it like?" The Doctor stared ahead of him for a long moment before telling her of the burnt orange sky, the mountains covered in trees with silver leaves and the way they would catch the light at sunrise and of the mighty citadel covered in a giant glass dome.
He was content in the knowledge that someone had at least heard of where he was from.