Whisk together the flour, sugar, salt, baking soda, and instant yeast in a large mixing bowl, or the bowl of a stand mixer.
Combine the milk, water, and oil in a separate, microwave-safe bowl (or in a saucepan on the stovetop), and heat to between 120 degrees F and 130 degrees F. Be sure to stir the liquid well before measuring its temperature; you want an accurate reading.
Pour the hot liquid over the dry ingredients in the mixing bowl and mix until thoroughly combined.
Using an electric beater, or stand mixer with the flat beater attachment, beat at high speed for 1 minute; the dough will be smooth and very soft.
Lightly grease an 8 1/2" x 4 1/2" loaf pan, and sprinkle the bottom and sides with cornmeal.
Scoop the soft dough into the pan, leveling it in the pan as much as possible.
Cover the pan, and let the dough rise till it's just barely crowned over the rim of the pan. When you look at the rim of the pan from eye level, you should see the dough, but it shouldn't be more than, say, 1/4 inch over the rim. This will take about 45 minutes to 1 hour if you heated the liquid to the correct temperature and your kitchen isn't very cold.
While the dough is rising, preheat the oven to 400 degrees F.
Remove the cover, and bake the bread for 22 to 27 minutes, till it's golden brown and its interior temperature is 190 degrees F.
Remove the bread from the oven, and after 5 minutes turn it out of the pan onto a rack to cool. Let the bread cool completely before slicing.
Notes
This recipe is from King Arthur Flour and is my favorite!