Preheat oven to 350ºF. Bring butter, salt and milk to a simmer in a large saucepan. Reduce heat and gradually mix in the cornmeal. Simmer while stirring until thickened, about 2 minutes. Remove from heat and add the pumpkin to the mixture. Meanwhile, whisk egg yolks, chives, thyme, cayenne pepper, ginger and nutmeg together in a large bowl. Whisk in the cornmeal mixture and set aside. In a medium bowl, beat the egg whites using an electric mixer until soft peaks form. Whisk 1/4 of the egg whites into the cornmeal mixture. Gently fold in the remaining egg whites. Pour the batter into a loaf pan. Bake for 40 - 45 minutes or until the bread starts to pull away from the pan. Serve warm.