Just that!
I'll start
I invited friends for dinner at mine. I made traditional dishes from where I'm from, sausage rougail, chicken cari and dessert.
A few days later they text me telling me to come to theirs for some food at dinner time.
I show up and bring a small jar of chilli peppers. One of the people who invited me goes "is that all you're going to eat?". I was confused and asked what they meant. They replied "It's everyone brings their own food."
I told them I thought they had invited me for dinner and they go "yes, we invited you to come to the house for dinner!".
They saw my face and said "don't worry, we can share some food with you!" before cutting a couple of raw carrots, aubergines, cherry tomatoes with some white sauce and putting them in the middle of the table.
They then served each other the meal they had made for themselves and digged in.
Note from MNHQ - we've had lots of nominations for this thread to be moved over to Mumsnet Classics and, as we're very generous hosts, we've done exactly this.