It's homemade peach preserves. I put them up myself, just before I went into the sanitarium.
6 seconds sound clip from the Holiday Inn (1942) movie soundboard.
You can hear this line at 00:13:57 in the Blu-ray version of the movie.
Quote context
[...]
- So long, Ted. Have a nice trip.
- I mean, yeah, thanks, I will.
- That reminds me, I forgot to give him a little Christmas remembrance I brought along.
- Got one here for each of you.
- Say, this is swell. What is it?
- It's homemade peach preserves. I put them up myself, just before I went into the sanitarium.
- Boy, do I go for those. Why, they're great on... Or even plain.
- Well, it's a long trip back to the farm, I think I'll get along.
- Will you say hello to Lila for me?
- But you gotta wait and catch the act. We got some new routines and then after the show...
[...]