Make the cornbread: Preheat the oven to 400°F. Butter two loaf pans.
In a bowl, combine flour, cornmeal, sugar, baking powder, and salt. Stir. In small bowl, whisk together eggs and milk, add to ingredients. Pour in melted butter. Stir until blended.
Divide batter between loaf pans and bake loaves for 25 minutes, or until pick or knife placed in the center comes out clean. Transfer to rack for 5 minutes. Flip out of pans and cool before cutting.
Make the stuffing: In a large skillet, heat oil over medium-high heat. Add onion, leek, celery, and jalapeños. Cook onions half browned. Add garlic, cook, 30 seconds. Add pecans and cubed cornbread. Stir. Add broth and parsley. Cook, 2 minutes.
Allow cooling before stuffing turkey. Mixture may bake in covered dish for 25 minutes.