Lightly grease a 3 qt. casserole dish, then combine cornmeal, salt and pepper. Mix together 3 cups water, yogurt, and olive oil. Pour mixture over cornmeal and stir until blended.
Bake cornmeal mixture uncovered for 25-30 Minutes. (Do not worry if the mixture does not look blended it will!) Stir cheese, herbs and prosciutto into the polenta (taste and add salt if needed).
Serve polenta within 5-6 minutes from removing from oven. If you are not ready for the polenta, turn oven off and let stay in oven until you are ready.