Okay, I'm searching for two specific stories. The pairing is Loki/ tony in both. The first one has a scene where Tony is severely injured, his spine shatters I think and he shortly after eats a apple, steps out of bed and surprises the rest The avengers by walking. Fury later tells him his spine was shattered.
The second is even more vague. I can only remember Tony eating an apple pie to later discover it was made with Idun's apples.
If Antonine know a good story with Idun's apples in I would love to read them :)