Preheat your oven to 400°F (200°C).
In a mixing bowl, combine the yellow cornmeal, all-purpose flour, baking powder, salt, and ground cumin.
Add the buttermilk and vegetable oil to the dry ingredients.
Stir in the diced green chili peppers and drained pickled jalapeños.
Add the shredded cheddar cheese and pepper jack cheese to the mixture, and stir until well combined.
Grease a 9x13-inch baking pan.
Pour the savory southwestern cornbread batter into the prepared baking pan.
Bake in the preheated oven for approximately 40 minutes, or until the cornbread is golden brown and a toothpick inserted into the center comes out clean.
Remove the cornbread from the oven and allow it to cool slightly.
Slice and serve your savory southwestern cornbread as a flavorful side dish or accompaniment to your favorite savory meals.