Season the prawns with the chili and salt and stir. In a wide saucepan, heat 4 tbsp olive oil on medium heat and braise the prawns for 1-2 min. while stirring constantly.
Take the prawns out onto a large plate, add more olive oil to the pan and braise the chopped onions in it until semi-transparent - about 5 min.
Add the can of tomatoes (which you can substitute with 7-8 fresh, blanched, peeled and chopped tomatoes). Pour the wine into the pan as well, add the garlic and oregano, stir and leave it to cook for about 10-15 min.
Then put the prawns back into the pan with the sauce and cook everything together for 1-2 min. Finally add the herbs and spices - basil, parsley, salt to taste.