6-8eggsdepending on how many eggs each person wants
In a cast-iron skillet or casserole dish, mix potatoes with olive oil, rosemary, salt, and pepper. Roast in a 425 degree oven for approximately 20 minutes (or until fork tender). Turn oven heat down to 375.
Add spinach to potatoes and spread evenly.
Add marinara on top of potato and spinach mixture.
Make small wells in the marinara mixture with the back of a spoon in which to place the eggs. Crack an egg directly into each well, or use a ramekin to crack each individually and pour into each well.
Sprinkle evenly with parmesan and mozzarella cheeses.
Bake in 375 degree oven for approximately 15 minutes, or until egg whites are set. Bake for a bit longer if you want the yolks to be hard.