To make the cornbread, Preheat oven to 450. In a bowl, mix the cornmeal, flour, salt and baking powder. Stir together. Measure the buttermilk and milk in a measuring cup and add the egg. Stir together with a fork. Add the baking soda and stir.
Pour milk mixture into the dry ingredients. Stir with a fork til just mixed. Don’t overstir.
In a small bowl, melt 1/4 cup of shortening in the microwave. Slowly add the melted shortening to the batter, stirring constantly til just mixed. In an iron skillet over high heat, melt the remaining 2 tablespoons shortening. Pour the batter into the hot skillet and spread to even out the surface. Cook on stovetop for 1 minute, then bake for 20 to 25 minutes til golden brown. The edges should be crispy. Slice into squares and serve with the beans.
For variation, stir 1 small can diced green chiles or 1 diced fresh jalapeño into the cornbread batter before pouring it into the skillet.