Lightly grease a 9 x 13 baking dish with butter or non-stick spray.
Warm a large skillet over medium heat, then add the chorizo. Using a wooden spoon, break up the chorizo, and cook, stirring occasionally for 5 minutes. Add 2 tablespoons of butter along with the onion, celery, garlic and a pinch of salt, and cook until the veggies soften and the mixture starts to caramelize (about 10 minutes), stirring occasionally. Add a splash of chicken stock to the pot to deglaze the skillet, then take it off the heat.
Crumble cornbread into a large bowl, leaving some pieces on the larger side. Gently stir in the pecans, warm chorizo mixture and parsley. In a medium bowl, whisk together the egg, chicken stock and 4 tablespoons melted butter. Drizzle liquids over the stuffing, and gently fold to combine. If the stuffing looks a little dry, add a splash more of chicken stock. The stuffing should look moist, but not wet. Season to taste with salt and pepper (I added about 1 1/2 teaspoons salt). Transfer stuffing to the prepared baking dish.
Preheat an oven to 350°F. Bake uncovered until hot (at least 150° in center) and lightly browned (about 25 minutes).Top with a sprinkling of parsley.