Preheat an oven to 375 degrees. Using a sharp knife remove the corn from the ear and place the cut corn into a bowl. Add the red pepper and onion to the corn. Combine the milk and eggs and whisk well. Add the salt, pepper and cayenne to the milk, pour the corn mixture into the milk and stir well. Lightly butter a large casserole, individual souffle dishes or pudding cups with the butter. Pour the milkcorn mixture into the souffle dishes and place into a roasting pan. The puddings will be baked in a water bath to keep them light and delicate. Place the pan on the middle shelf of the oven and fill the roasting pan halfway with warm water. Cover the pan with aluminum foil and push the rack back into the oven. Cook the puddings for 35 to 40 minutes or until the puddings are firm but not rubbery.