I've had great luck with preparing this dish early Thanksgiving morning and re-heating when it's almost dinner time. Just under bake it slightly at 20 minutes, then cover with foil and put into a 350° oven for 10 minutes before serving. —Big City Kitchen
Preheat oven to 400°. Butter or spray a 2 quart casserole dish and set aside. In a medium saucepan, melt butter and add corn kernels. If using fresh corn, cook for a few minutes to soften kernels up. Add milk, cornmeal, salt, pepper, cayenne and nutmeg. Bring to boil, the reduce heat to medium-low, stirring frequently until mixture has thickened slightly, about 3-4 minutes.
Remove from heat and stir in cheese and scallions. Let cool until warm to the touch, about 15 minutes. Stir in egg yolks until combined.
Meanwhile, beat egg whites with a pinch of salt until soft peaks form. Stir in 1/2 of the whites to corn mixture until combined, then gently fold in remaining whites. Pour into prepared dish and place in oven, reducing temperature to 375°. Bake until browned on top but slightly loose in the center, 25-30 minutes. Let cool for a few minutes before serving.