Preheat the oven to 375°F. Lightly grease a 9" square or round pan (a cast-iron skillet will work fine, too), shallow 1 1/2 quart casserole dish, or 12 muffin cups. Weigh your flour and cornmeal; or measure each by gently spooning into a cup, then sweeping off any excess. In a medium bowl, whisk together the flour, cornmeal, sugar, baking powder, baking soda, and salt. In another bowl or large measuring cup, whisk together the milk, melted butter, vegetable oil, and egg. Pour the liquid all at once into the flour mixture, stirring quickly and gently until just combined. Don't over mix: stir the batter just enough to bring it together and evenly moisten the ingredients. Spread the batter into the prepared pan, or scoop into the muffin tin. Bake the bread for 20 to 25 minutes, until the edges just begin to pull away from the pan and a cake tester or paring knife inserted in the center comes out clean. If making muffins, bake for 14 to 16 minutes.  Remove the bread from the oven and cool it on a rack for 5 minutes before cutting; serve warm. Store any leftovers, well wrapped, at cool room temperature for a few days; freeze for longer storage.