To make the tamales, beat the lard in a bowl with a wooden spoon to soften, then add the flour, baking powder and salt and continue to beat. Slowly add the warm water, beating to form a stiff dough. Turn out onto a clean surface and knead for a couple of minutes, until soft. Wrap the dough in cling film and place in the fridge while you prepare the filling.
To make the filling, heat the olive oil in a saucepan and fry the onion, garlic, tomato, cumin and chilli for 10 minutes, add the kidney beans and a splash of water and cook for a further 10 minutes. Season with salt and pepper, add the coriander, then mash the beans roughly with a potato masher.
To make the salsa, bring a pan of water to the boil and cook the corn on the cob for 10 minutes, until cooked. Remove the corn on the cob from the pan and allow to dry out.
Heat a griddle pan until hot then cook the corn on the cob until charred all over. Allow to cool then use a knife to cut the kernels from the cob. Place the kernels in a large bowl and set aside.
Place the onion in a colander, sprinkle with salt and leave for five minutes, then rinse and add to the bowl with the corn. Add the lime juice, garlic, chillies, parsley and oregano and mix well.
To assemble the tamales, place a tablespoon of dough on a square of greaseproof paper and use your hands to flatten it into a rectangle shape. Place a spoonful of the beans in the middle and sprinkle with the Cheddar then fold over the sides and the ends to form a parcel and press down to seal. Wrap with the greaseproof paper, tie with string then repeat until you run out of dough.
Place the tamales in a steamer and cook for about an hour. Remove the tamales and carefully unwrap. They can be served as they are or they can be pan-fried on both sides until golden-brown. Serve with the salsa on the side.