Mortar the sweet paprika, the cummin, salt and add the vinegar. Mix it all together.
Wash the meat and dry it with kitchenpaper, cut the meat in blocks and addit to a bowl.
Cover the meat with the marinade (result of mortar), place it in the fride for around 4 hours.
Heat up the oil in a fry-pan and fry the meat until it's golden brown all the sides.
Remove the meat out of the pan but leave the oil in it and add the meat to a pot.
Add the marinade and the orange juice to the meat and a little of water until it's enough to cover the meat.
Cook it on low fire until the meat is soft.
In the mean while wash the sweet potatoes, peel them and cut them in about 2cm high slices.
Cook them in boiling water with salt until they're soft.
Serve the meat together with the sweet potatoes.