Bring potatoes to a boil and cook until just tender. (Do not overcook them). Drain and let cool. Carefully cut slices into quarters.
Sauté leeks, mushrooms & prociutto in olive oil and season with Italian seasoning, salt and pepper. Cook until leeks are tender. Let cool.
Whisk milk with beaten eggs. Carefully fold the potatoes, leeks, mushrooms, prociutto and shredded cheese into egg mixture.
Spray Redi Set Go Oven with cooking spray on both sides. Pour in egg mixture and cook until center is done, about 15 minutes. Cut into quarters and serve immediately.