Toss it.
If he gave it up, that doesn't mean put in something else. You're supposed to be supportive.
LOL. My dd gave up red meat, pork and dairy. That was a choice she made for herself, not for everyone else in the house. If she doesn't eat a component in a meal I make she's free to make her own meal. I'm sure since the OP's ds stayed home while OP was away that he is perfectly capable of making his own meals too.
OP I was going to suggest freezing it in TBSP portions so it can be used as needed in coffee or other recipes, but I'd have to go with that Panera copy-cat cream of chicken soup, yum!