Cut the sweet potatoes and boil with a little bit of salt until they are soft. Heat some oil and when ready add the sweet potatoes and allow them to gild. When they take some color, add the butter, the garlic, the chopped onion and the chopped leek. Mix well, take out of the fire and separate. In a recipient add the oregano and the paprika to the sweet potatoes and mix well. Serve and enjoy!