Wash and pat-dry the potatoes, then pierce them with a fork. Place them on a lightly greased baking sheet. Bake for about 1 hour, in a medium-hot oven, until the potatoes are cooked through (test with a skewer). Let them cool (you can store them in the fridge until needed).
Cut the potatoes in half (lengthwise). Using a spoon, scoop out the potato flesh.
Rub some oil inside the skins then place them, skin side down, on a lightly oiled baking sheet. Bake for 10 minutes at 170-190°C, until crispy and golden.
Meanwhile, chop the onion and the chorizo and put these in a frying pan. Heat the pan and gently cook until the onion is soft (the chorizo should release its fat).
Thinly slice the red pepper.
Mash the potato flesh with a fork, season with salt and pepper to taste. Add the chicken meat, olives and red pepper slices. Add the Chorizo mixture, including the fat and combine well.
Carefully fill the crispy potato skins with the Chorizo mixture.
Bake in the oven for about 10 -20 minutes to warm through.
Serve warm with chopped parsley scattered on top.