I've got an event coming up, and it got a bunch of "stations" at different homes, one of which is mine. I'll likely not be in my house until I sneak out about 15 minutes before the crowd heads here. I've got sweet things covered, along with a drink, but I need something savory, and I'd like it to be hot, if possible, but I need it to be made ahead, and to be ready to serve in about 15 minutes. So I'm imagining something I can make the day before, and the when I get to the house I can heat the oven (5 minutes), and have cooked/heated after about 10 minutes in the oven. It also needs to be something that is a good finger food, as there will be activities and speaking while we eat.
Also, I am an unenthusiastic cook, and my ability to find more unusual ingredients is somewhat limited here.