Preheat the oven to 375°.
Add the ingredients for the sauce into a blender blend until smooth.
Save ¼ of the sauce for later and pour the rest into the 10-12in cast-iron skillet and spread around to smooth it out evenly in the pan.
Wash all of the veggies and slice them very thin - less than ¼" thick is best.
Start arranging the slices in a spiral around the skillet, alternating between veggies.
When the skillet is full, drizzle the remaining sauce over the top of the veggies.
Lay a piece of parchment over the top of the skillet and bake for 1 hour.