Preheat oven to 325 degrees.
In large cast iron skillet - arrange zucchini, squash, potatoes, and tomatoes in an alternating circular pattern around outside of pan. Then make an inner circle going the opposite direction. Finally, fill in center to make a "flower-like" shape.
Drizzle olive oil around the outside of pan and in the cracks of veggies. Then sprinkle with 2 tsp. of salt.
Place skillet uncovered in oven for 40 minutes.
Move skillet to stovetop and cook over medium-high heat until juices are evaporated (about 15 minutes).
Meanwhile, in a large bowl - combine eggs and 2 tsp. of salt. Whisk well.
Once juices are evaporated - gently add eggs to skillet and allow to settle for about 30 seconds.
Move skillet back to oven and bake for 30 minutes.
Remove from oven, slice like a pie, and enjoy!