Cook the potatoes in a pan of water until tender, then drain. Let them cool. Keep refrigerated until you’re ready to cook the dish.
Cut the chorizo into small pieces. Thinly slice the onion, celery and finely chop the garlic. Put all in a frying pan and turn the stove on to low heat. You might need to add a drop oil. Stir occasionally.
Meanwhile, dice the sweet potato and red pepper. Prepare the greens.
When the chorizo has released its fat and the onion & celery have softened, add the chopped veggies and stir in the dried herbs. Stir for a minute, then add the tinned tomatoes. Season with salt and pepper. Put a lid on and cook for 25-20 minutes over medium heat.
Add the greens and some water if the sauce is too thick. Cook for about 5 minutes. You should get a thick sauce. Stir in the coriander leaves.
Cut the boiled potatoes into ½ cm thick slices .
Cover the base of a deep, medium-sized baking dish with some potatoes, then add half of the chorizo sauce. Scatter the chicken on top.
Add another layer of potatoes, then spoon the other half of the chorizo sauce on top.
Cover the top with the remaining potatoes slices, then scatter the cheese all over them.
Bake in a pre-heated oven (at 180°C) for 20 minutes, until the cheese has melted.
Serve with soured cream, if liked.