Inspired by some of our local festivals here in France, this would be a festival celebrating local food and art with edible sculptures!
Here in the south of France we have many festivals celebrating local produce: the grapes / wine, the apples, the figs, the mushrooms, to name a few. We also have art festivals. So how about combining the two, a bit like a village near to me does and make edible sculptures? This is an apple festival and the sculptures are utterly amazing as you can see from the photo.
But it needn't be limited to apples. Local artists could be commissioned to design sculptures made from other local foods (which are not too perishable), with the aim of creating an attraction and catch people's attention. The festival could combine many great ideas already proposed in this challenge: food fairs, farm tours, local restaurants involvement, projects for schools, etc. Arjan Tupan's concept highlighted the Queensland Harvest Festival which might be the perfect time to hold the festival.
As part of the festival there could be big community meals, which is another tradition here in France. Villages come together to eat, everyone bringing their own cutlery (and sometimes chairs), preparing and eating local produce together, having a great time and getting to know each other.