Preheat the grill and set the oven rack at about 15cm from the heat source.
Line a baking tray with aluminium foil. Cut the capsicums in half from top to bottom; remove the stem, seeds and ribs then place cut-side-down onto the prepared baking tray.
Cook under the grill until the skin of the capsicums has blackened and blistered, about 15 minutes. Place the blackened capsicums into a bowl and tightly seal with cling wrap. Allow the capsicums to steam as they cool, about 20 minutes. Once cool, remove the skins and discard.
Preheat the oven to 190 degrees C. Grease a 20x30cm baking dish.
Meanwhile, heat a large frypan over medium-high heat and stir in the chorizo. Cook and stir until crumbly, evenly browned and no longer pink. Drain and discard any excess grease, then pour into a large mixing bowl and allow to cool.
Chop the roasted capsicums and place them in the bowl with the chorizo and bread cubes, onion, celery, cranberries, garlic, parsley, thyme, rosemary, poultry seasoning, salt and black pepper. Pour the chicken stock over the top and stir until evenly blended. Pack the stuffing into the prepared baking dish.
Bake in the preheated oven until the stuffing is golden brown and crispy on top, about 30 minutes.