Perhaps it was one of those mentioned in Wikipedia?
During the Second World War, a number of severely damaged aircraft were deliberately landed on grass airfields ashore. In at least one case, an aircraft that made a grass landing was repaired to fly again.[9]
There appears to be one coming up on Google (search = "Sunderland landing on grass at RAF Aldergrove") but I'm not logging in/signing up to pinterest to find out!
But I did manage to read a photo caption "The masterly landing was made on the grass, without injury to the crew, piloted by Gordon Singleton. Although eventually recovered Sunderland T9114 never flew again." Annoyingly, it's not your aircraft! >>>
https://www.youtube.com/watch?v=0ZfVEoZmt-c