Some things that have gone over well w/ our parties: Mac & Cheese, Roast Beef w/ gravy in the crockpot, meatballs.
I found a great EASY mac & cheese recipe that my girls love. Cook the pasta, keep a little of the water before draining. Once you strain the pasta, cut up a block or two of Brie (depending on how much pasta) & throw it in the pot, dump the pasta on top & let it melt the cheese a bit & then stir to distribute. Take some fresh basil if you have it, roll the leaves up & then slice thin, throw those in too. If your kids like, take some grape tomatoes, cut in half & throw those in as well. You can use the saved pasta water if it seems a little dry. I also sometimes will use half/half or cream if I have it. My kids love this & have been begging for it.
I like to find things that are easy to throw together in advance or quickly so I don't have to be away from the party for too long.
I also have done mexican for a Dora party but...honestly, the kids didn't remember the food theme so going w/ very easy, very accessible food is just the way to go now for me.