Peel and devein the prawns then rinse and drain well. Squeeze over the lemon juice and rub with half of the garlic. Cook the prawns lightly in the butter then remove and set aside.
Add the oil to the butter and saute the onions until soft. Mix in the tomatoes and ginger and cook for 5 to 10 minutes then add the white wine, stock and remaining ingredients.
Stir well and simmer for 20 minutes, adding a little water if needed. Serve with ice or cornbread.