I accidentally ate someone’s lunch what do I do …….

Ok so I work in a grocery store and yesterday two of my coworkers were cooking Indian food for free lunch. Since it was my day off yesterday my coworker said she'll set some aside for me in the fridge. So when I was having my lunch today I grabbed what I thought was for me. But it wasn't. I found what was set aside for me later. I feel terrible. There are so many people working I don't even know half of them