Preheat the oven to 350 degrees F.
Carefully remove the corn from the cob with a knife and put in a food processor. Transfer to a large bowl. Coarsely puree with salt, pepper, and nutmeg. In a saute pan, add the oil and the onions and saute until translucent. Add the onions to the corn mixture. Add the beaten eggs, milk and half of the grated Cheddar and combine. Use 2 teaspoons of oil to coat a 13 by 9-inch baking dish. Transfer the corn mixture to the dish and top with the rest of the grated Cheddar. Place the dish in the oven and bake for 30 to 40 minutes or until the top of the casserole is golden brown.