Peel and chop the onion finely. Peel and crush the garlic.
Chop the basil.
Peel the sweet potato and cut into small pieces. Cook the sweet potato in boiling water for 15-20 minutes until tender.
Heat the olive oil and fry the onion until soft. Add the garlic and minced lamb and fry until the lamb is cooked.
Add the tomato puree, chopped tomatoes, water, stock cube, cinnamon and basil and stir.
Bring to the boil and simmer for 10 minutes.
Drain the sweetcorn and add to the meat mixture, stir and simmer for 5 minutes.
Drain the sweet potato.
Pre-heat the grill to medium.
Spoon the lamb into a serving dish and top with the sweet potato.
Grate the parmesan. Sprinkle the parmesan on top of the lamb and potatoes.
Grill for a few minutes until the cheese is golden brown.