Before you start: you want to use stale or toasted cornbread. To dry it out, cut the cornbread into large chunks and arrange in a single layer on a sheet pan. Tent loosely with foil and set it out overnight. Alternately, bake at 350°F for 25-30 minutes.
Preheat the oven to 350°F and spray a casserole dish with nonstick cooking spray.
Add the chorizo to a large skillet over medium-high heat and brown it, breaking up the pieces, until no pink remains. Transfer it to a paper towel lined plate or bol and drain any excess fat.
Turn the stove down to medium heat and add the garlic, onion, and celery and cook until fragrant and the onions are soft, 6-8 minutes. Stir in the parsley, sage, rosemary, salt, and a pinch of black pepper. Pour in 1 1/2 cups of the chicken broth.
Place the stale cornbread and chorizo in the prepared casserole dish. Pour the butter, herb, and stock over the chorizo mixture and toss gently to coat.
Mix the eggs with the remaining stock in a bowl or measuring cup and pour it over the chorizo stuffing. Gently fold to combine.
Bake in the preheated oven for 45-50 minutes, until it's set (internal temperature should be 160°F). Tent with foil if it starts to get too brown.