Place a 9-inch or 10-inch cast iron skillet or an 8-inch or 9-inch round cake pan in a cold oven. Preheat oven to 400° F, leaving the skillet or pan in the oven while it heats.
Meanwhile, whisk together the cornmeal, flour, sugar, baking powder, salt, and baking soda in a large bowl.
Add the buttermilk, butter and eggs. Stir to combine. Fold in jalapeño, cheese and chives.
When the oven has come to temperature, pour oil into the hot skillet or pan. Use a brush to evenly spread the oil. Pour batter into the hot, greased skillet. Bake for 20-25 minutes, or until golden brown and a toothpick comes out clean.
Notes
Use afinely-ground or medium ground yellow or white cornmeal. Coarse cornmeal will give the bread a more grainy (rather than soft) texture.
Let the batter rest for 5-10 minutes before baking, if you have the time. This allows the baking powder to activate and incorporate more air.
Preheat the skillet or baking pan in the oven to achieve crisp, golden brown edges.
Don’t over-mix the batter or it will become too dense, and you'll end up with dry cornbread.
To check if the cornbread is done, insert a toothpick into the center and make sure it comes out clean. Don't cook for too long, or it can dry out.
This bread is not very spicy if you remove the seeds and ribs from the jalapeño. If you prefer a spicy cornbread, leave some of the seeds and ribs intact, or increase the amount of jalapeño in the batter.
For a colorful red touch, stir in diced red bell pepper or pimento.
Use any good melting cheese in lieu of the cheddar. Pepper Jack is great for a spicy kick, or try Colby, Monterey Jack, or a blend of cheeses.
Sweet Mexican Cornbread: if you'd like the bread to be sweeter, increase the sugar to ¼ cup (or more).