Heat the oven to 190°C (170° fan) 375°F gas 5.
Grease a baking dish.
Heat the oil in a pan and cook the onions and garlic until softened.
Stir in the spices, tomatoes and sugar and simmer for 15 minutes.
Stir in the shrimps, salt and pepper and transfer to the the baking dish.
Sprinkle with the cheese and oregano and bake for 15-20 minutes until piping hot.