Preheat oven to 400F. Grease shallow 1 1/2 qt casserole.
In 4-qt saucepan, heat water, 1/2 tsp salt and half of milk to boiling on high. Reduce heat to med-low and whisk in cornmeal in slow, steady stream. Cover and simmer 10min or until mixture is thick - whisk frequently.
Remove from heat and whisk in butter until melted. Continue whisking and add remaining milk. Whisk in eggs, then baking powder.
Stir in green onions (reserve a few for garnishing), corn, Parmesan, and 1/4 tsp pepper until mixed. Transfer to prepared dish and spread in smooth, even layer.
Bake 45min-1hr or until golden and knife inserted in center comes out clean. Garnish with remaining green onions.
Nutrition Info Per Serving: Calories 197 Total Fat 8 g Cholesterol 78 mg Sodium 126 mg Potassium 239 mg Total Carbohydrate 23 g Dietary Fiber 2 g Sugars 4 g Protein 7 g