Add the spinach and turn off the heat. Stir until the spinach wilts and the moisture cooks out a bit. Season with salt and pepper.
Layer more than half of the vegetables on the bread in the casserole dish.
Add more bread slices on top of this layer.
Scramble the eggs very well (with the milk, if using) in a bowl using a whisk or a fork, and season with salt and pepper. Pour the eggs on top of the layered vegetables and bread. Turn the slices of bread that are on top, and press down, so both sides get coated with egg.
Add the remaining vegetables from the pan, and the raw zucchini and cilantro, on top.
Cover tightly with aluminum foil and bake for 40 minutes.
Remove the foil and continue to bake until the top is browned and when you press on the middle with a spatula, no egg oozes out.
Enjoy your very fresh farmer's market breakfast! The veggies on top will have a little crisp to them from the oven. Delicious!
Recipe by My Utensil Crock at http://www.myutensilcrock.com/2018/06/15/farmers-market-spring-breakfast-egg-bake/