Using a knife or mandolin slice your zucchini, squash, eggplant and tomatoes into 1/8th inch thick slices
Using a paper towel wipe down the inside of you cast iron pan with 1 tbsp olive oil, next place the balled up paper towel in the pan on the outside to act as a base to hold your veggies as you spiral them around the outside of the pan.
Continue to spiral the ingredients in the pan until it is full. Drizzle with olive oil and season with salt & pepper along with any fresh herbs or grated Parmesan you would like to add
Bake for 30- 40 minutes until veggies have caramelized on top, let rest for 5 minutes before serving.