Wash and pat dry the potatoes, then pierce them with a fork and place them in a baking tray. Season with salt. Bake for about 1 hour at around 190°C, until the potatoes are cooked through (test with a skewer). Let them cool.
Cut the potatoes in half (lengthwise). Using a spoon, scoop out most of the potato flesh, making sure the skin doesn’t tear.
Using a brush, lightly oil the inside of the potato halves then put them, skin side down, on an oiled baking sheet. Bake for 8-10 minutes at around 190°C until crispy and golden.
Meanwhile, cut the chorizo into tiny cubes and finely chop the onion and tomato. Heat a frying pan, add the chorizo & onion and gently cook until the sausage has released its fat and the onion is soft. Add the tomatoes and cook for a couple of minutes. Add the chipotle paste and the tomato purée and stir for a minute. Add the beans and corn, heat through. Add the potato flesh and combine. Season to taste then add the chopped herbs.
When the potato skins are crispy , stuff them with the mixture. Grate some hard cheese on the top, if you like, then bake or grill for about 10 minutes until golden.
Serve warm.